Betty: "Cheryl, get the hell out of my house before I kill you."
―Betty to Cheryl, after the latter accused her sister Polly of killing Jason[src]
The relationship between Cheryl Blossom and Betty Cooper is hard to define, but the two can currently be called rivals, though frenemies may be more accurate. They both care for each other but haven't openly admitted it, therefore they can be seen as friends in denial about their friendship.
Cheryl and Betty met at some point before the start of the series. They share a connection, as Cheryl's now deceased twin brother Jason dated Betty's older sister Polly, and apparently, their relationship did not end on good terms. After her brother's death, Cheryl started to despise Betty and continuously humiliate her whenever she got a chance.
During the previous school year, Betty tried out for the cheer squad but was rejected by Cheryl who claimed Betty was too fat.
When Veronica Lodge moved to Riverdale and enrolled at Riverdale High School, she befriended Betty and managed to convince her to join the River Vixens cheer squad, which was run by Jason's sister, Cheryl Blossom. When Betty and Veronica failed to impress Cheryl, she put Betty in an uncomfortable spot in which she was forced to explain her sister's mental heath in front of the entire cheer squad and Veronica, causing Betty to self-harm by clawing at her hand with her nails so as not to be provoked. However, Veronica managed to save her new friend by telling Cheryl that they came as a package deal, otherwise Veronica would refuse to join, and Cheryl reluctantly accepted and allowed both Betty and Veronica to join the River Vixens. However, Cheryl took delight in tearing Betty and Veronica's burgeoning friendship apart at her party later that night. Cheryl manipulated Veronica into playing Seven Minutes in Heaven with Archie Andrews, who she knew Betty had feelings for. Betty left the party in distress.
Cheryl took advantage of this situation and feigned being nice to Betty and offering herself as an alternative friend. She went round to her house and pretended to be apologetic about her past treatment of her, but was really digging for information about Polly. It was revealed that she believed Polly had killed Jason, and so Betty forcefully told Cheryl to leave her house before she killed her.
Cheryl encountered Betty and Veronica plotting to take revenge on certain members of the football team for slutshaming them. When told they had a book listing their conquests, she was disbelieving, certain that Jason would have told her about it if it was true. When they stole the book, though, she discovered that Jason had not only known about it but had participated, as Polly Cooper's name was listed in the book. This forced her to reevaluate her opinion of her brother, and she apologized to Betty for his actions and they burned the book together.
After Polly Cooper's escape from the Sisters of Quiet Mercy group home, and an unsuccessful search for her, Alice Cooper held a press conference and, much to Cheryl's surprise, revealed to the entire town that Polly was pregnant with Jason's child. Polly was eventually found by Betty, hiding in the attic of the Cooper house, where she revealed that their parents were trying to for her to give the baby up for adoption. Betty was speaking to Veronica in the student lounge the next day about Polly's situation when they were were interrupted by Cheryl, who wished to help Polly and the baby. Reluctantly, Betty revealed that she knew where Polly was and that she needed money for a place to live and medical supplies, to which Cheryl responded that her parents would be more than willing to help.
That night, Betty met up with Cheryl and her parents at Pop's Chock'lit Shoppe, where they assured Betty that they could assist Polly with emotional and financial support, all Betty had to do was trust them enough to tell them where Polly was. They were set to meet again the next night, however, Cheryl came alone to warn Betty and Polly of her parent's ill intentions; they did not care about Polly, they just wanted the baby. Cheryl told Betty and Polly to leave, before her parents arrived.
With Polly living with the Lodges at The Pembrooke, Jughead, Betty, Cheryl, Archie, Veronica, Kevin and Valerie analyzed Polly's dilemma, in which the Coopers wanted her but not the baby, and the Blossoms wanted the baby, but not her. Veronica suggested that they throw Polly a baby shower, which would force the Coopers to finally start communicating, which Cheryl was in full support of.
On the night of Polly's baby shower, Cheryl came bursting through the front door of Hermione's apartment with a brand new, expensive stroller for Polly and Jason's child. All Cheryl asked for in return was that she be named the baby's godmother, unaware that Polly had earlier named Betty the godmother. A little later in the night, as Polly opened the gifts, Cheryl expressed her desire for Polly to stay with them at Thornhill, which Cheryl's mother assured Polly was a genuine offer. However, this started an argument between Penelope Blossom and Alice Cooper. Cheryl stepped in in support of her mother, but Betty quickly rebuked her as she was not helping the situation. After the shower, Polly decided to go live with the Blossoms.
After attempting to contact Polly to no avail, a brief confrontation took place between Betty, Jughead and Cheryl, in which Betty demanded that she be allowed to talk to Polly. Cheryl told her they shouldn't be fighting but celebrating as she revealed that a doctor confirmed Polly was expecting twins, which Betty was unaware of. She was shocked to learn that her own sister did not tell her, but she pleaded with Cheryl to at least deliver a message, for Polly to call their mother as she missed her, despite her best efforts to hide it. Cheryl agreed to pass on the message but made no promises that Polly would care or respond.
Betty comforted Cheryl about her feelings of the nightmare not really being over. When Betty found out that Clifford Blossom is Jason's killer, she immediately called Cheryl and told her to get out of Thornhill.
After Archie's father was shot and sent to Riverdale General Hospital, later during the day, Kevin and Betty were discussing about Betty's love life. Their conversation ended when they spotted Cheryl coming into the hospital with a body wrapped in up bandages. They later go to talk to Cheryl to ask her if the body covered in bandages was her mother, which Cheryl confirmed that it was. Informing them that their house burnt down.
A couple days later, Jughead was informed that his father would possibly be spending 20 to 40 years in prison, as Jughead was worried for what would become of his father once his court trail began. He later went to see an attorney named Penny Peabody, who informed Jughead that the only way he could help his fathers case, was to speak to the Blossom Family to get them to make a statement that they don't hold FP accountable for the death of Jason Blossom, stating that they forgive him for his part in the crime committed. Jughead later headed over with Betty to the Thistlehouse, where Cheryl and her mother, Penelope where staying. To convince them to making a statement that would help in FP's case. However, the Blossom's were reluctant to do so, refusing to help Jughead. As Penelope and Cheryl wanted FP to suffer for what happened to Jason. As Betty later pointed out to Cheryl that it wasn't FP who killed her brother, it was her father.
Later, Betty stopped by the girls locker room, as she came by to have a chat with Cheryl. Betty blackmailed Cheryl into testifying on the behalf of her family for FP's court trail, without Jughead knowing about it. As she threatened Cheryl that she would show everyone of the copied footage that was made an kept on Jughead's laptop, of the night her father, Clifford, killing Jason in cold blood. Ashamed by her fathers sins, and how it would impact her and her mother, Cheryl was willing to make her statement to prevent the footage from getting out.
The next day, Cheryl sat in the student lounge, hidden from Betty and Kevin as the two of them conversed over his failure to show up at Veronica's place to meet her father. Kevin claimed that something else came up. Something in the woods, Betty asked. Insinuating that he had broken his promise to refrain from cruising. Kevin hoped that Betty wouldn't take what he was about to say the wrong way, but he listened to Betty obsess over Archie for years. And she continued the pattern with Jughead. She didn't need Kevin's permission to date them, and there was no legitimate reason for why he would need her's. He told Betty that what he did in the woods was none of her business, before abruptly leaving. It was then that Cheryl made her presence known. Button down Kevin Keller has a sex drive, so what? Cheryl asked. Kevin used to be a lonely, awkward, fat boy with acne. Now, he's a smoke show, though, in his mind, he was still unattractive, so now, he is seeking validation, Cheryl explained.
The following night, as Cheryl sat in a booth alone at Pop's Chock'lit Shoppe, she noticed Kevin heading out for a run, presumably to resume his cruising of Fox Forest. Oh Kevin, you precious, beautiful, compulsive, piece of trash, she remarked, before devising a plan that would surely satisfy her craving for trouble and drama. Cheryl called Betty to inform her of Kevin's run, presumably knowing that it would end badly between the two of them. Cheryl's suspicions proved to be correct as the two of them found Kevin cruising the woods. Betty was disappointed that he broke his promise. She wanted him to have more respect for himself. While they had been friends for a long time, Betty had no idea how difficult it was being a homosexual male in such a small town. Betty acted as if they had the same set of options, when in reality, this couldn't be further from the truth. Kevin went on to explain that she lived in a pale-pink world of milkshakes and first kisses, where her biggest romantic dilemma is whether she is going to date Archie or Jughead, except for when she exploring her BDSM sexuality, which again, she's allowed to do, but he's not. Fox Forest was all he had to work with. So, he didn't need Betty following him just to tell him how disgusted she was with it all. If she couldn't accept what he did, then they weren't truly friends.
Although, they had very little interaction, Betty and Cheryl attended the party in Nick's hotel room, along with Veronica, Archie, Reggie, Josie, Valerie, and Melody. Cheryl told Archie to keep up as Nick told a story about his run-in with Gal Gadot. After a few drinks, Nick suggested they turn up the party with some Jingle Jangle that he scored from Reggie. While Betty and Archie weren't interested, everyone else, Veronica included, was more than willing to indulge. Suddenly, Archie had a change of heart, and decided to join them, making Betty the odd man out, so to speak. As all her friends got high and partied under the influence, Veronica attempted to encourage Betty to have some fun, as she was without Jughead for the night. Betty told Veronica that she was making a fool of herself by acting like some privileged, shallow, airhead party girl. Betty claimed that she was only saying what they were all thinking, that Veronica was merely a friend of circumstance and that she wasn't who she pretended to be. Why should they be surprised, Betty asked. Like father, like daughter, she added. Veronica may have fooled the rest of them, but she hadn't fooled Betty. She saw Veronica for what she truly was, a bad person.
While tanning outside Thistlehouse, Cheryl received a surprise visit from Betty, who initially claimed that she was stopping by to check on her after the incident with Nick, but after Cheryl called Betty out on having ulterior motives, even referring to Betty as "Invisible woman" due to the fact that Cheryl could see right through her, Betty confessed that she was writing an article for the Blue and Gold on Jingle Jangle inundating Riverdale. Betty asked if she had every heard of "The Sugarman", which she had. When Cheryl and Jason were younger, their mother used to tell them tales of how their father was friends with the so-called Sugarman. And if they were bad, he'd sneak into their rooms at night, steal them from their beds, and whisk them away, nevermore to be seen. Betty asked if it was possible that the Sugarman was real, and if so, could he have been involved with her father's drug business. Cheryl was vexed by Betty's memory defiling insinuation. She reiterated the previous story, assuring Betty that the Sugarman was nothing more than a poison confection spun by her mother to scare children. Like the Sandman or Krampus.
Betty and Cheryl attended the drag race being held near Herk Harvey bridge between Archie and Jughead and two members of a Southside gang called the Ghoulies. They sat alongside Kevin, Reggie and Veronica as the race was about to commence. Usually, the honors of flag girl go to Toni Topaz, a member of the Southside Serpents, but with Cheryl feeling as if she was born for the moment, she informed Toni, who she referred to as "Cha Cha" (the "First Lady of Drag Racing", Shirley Muldowney) that she would be replacing her this time around. Cheryl took to the center of the road, asking both drivers if they were ready before waving her flag, signaling the start of the race, which was later intercepted by Sheriff Keller and the police department, thus ending the event as everyone scattered at the news of police involvement.
Though, they did not speak, Betty and Cheryl attended Kevin's Secret Santa gift exchange along with Archie, Reggie, Veronica, Jughead, and Josie. They all gathered in the student lounge at school, where the exchange took place. It was Veronica's turn. She opened her gift from Josie, which awkwardly enough was a gift certificate for a couples massage. Hoping to lessen the awkward tension, Josie suggested that Veronica use the certificate to take someone other than Archie, given that they were no longer together, such as Betty or her mother. With the sudden awkwardness being too much to withstand, Cheryl was thankful to learn that Betty was the last exchange of the evening. Based on the wrapping of her present, Betty immediately knew that it was Archie that picked her name. Betty unwrapped the gift to find and old read-a-long record that she and Archie used to listen to when they were younger, entitled "The Swiss Family Robinson". Archie informed her that he and his father found it while they were cleaning out the garage. They were then surprised by the unexpected arrival of Moose and Midge.
Christmas Eve night, Cheryl received an unexpected visit at Thistlehouse from Betty and Archie. They came hoping to speak with Nana Rose. They had questions for her about something that happened along time ago in Riverdale. A man known as the Riverdale Reaper massacred a family one night and in return, a group of people decided to take justice into their own hands. Betty asked if she was apart of said group. Though, before Nana Rose could responded, Cheryl interjected, asking if their line of questioning was a Christmas inquest. Archie informed her that they wouldn't be questioning her grandmother if it wasn't important. A man's life was on the line. Betty then repeated to question, asking if Nana Rose was present when the man was executed for revenge. Nana Rose informed Archie and Betty that she did not attend the execution, as no girls were allowed. She was instructed to stay at home while a group of men took care of the rest. Betty then asked where the man was hung. However, As Nana Rose explained, he wasn't hung, rather buried alive. A proper burial, so to speak. Where did they bury him, Archie asked. Rose advised Betty, who she mistook for Polly, to ask her grandfather given that he participated in the execution. Rose had a picture of them, smiling at the burial grounds, just under the devil's hand. Nana Rose then called out for Cheryl. Claiming that she fell ill, she requested that Cheryl take her to her room. With that being said, Cheryl told them that their "reindeer games are over" and to get the hell out. She later watched from her bedroom window as Archie and Betty shared a kiss just outside Thistlehouse.
Cheryl entered the ladies restroom at school to find Betty vomiting into the toilet. She asked if Betty was okay and even offered to get her a towel, but Betty insisted that she was fine. So Cheryl left her on the stall floor to recover alone.
A couple days later at school, Cheryl approached Betty by her locker to tell her the truth about her father. Despite telling Hal that she was going to keep his secret to herself, Cheryl had changed her mind after she kept tossing and turning in her canopy sleigh bed all night long, thinking that she'd want to know. While she took no pleasure in what she was sharing with Betty, she thought it best if Betty knew that her father was having an affair with Cheryl's mother.
Cheryl: "Tell Veronica about your sister and my dear brother."
Betty: "Polly and Jason dated."
Cheryl: "'[scoffs] I wouldn't say "dated"."
Betty: "It didn't end well."
Cheryl: "In fact, Jason's probably why your sister had a nervous breakdown and now lives in a group home, isn't it?"
Betty: "That's what my parents think."
Cheryl: "What do you have to say about that, Betty? Go ahead, the floor is yours. Whatever you've been dying to spew about Jason and how he treated Polly, unleash it. Destroy me. Tear me a new one. Rip me to shreds. Annihilate me."
Betty: "I just..."
Betty: "I just wanted to say I'm sorry about what happened to Jason. I can't even imagine what you and your family must be going through."