The father-son relationship between Jason and Cliff Blossom was clearly riveting. It is presumed their relationship was filled with hatred, with which Cliff was grooming Jason to take over the family business. However, Jason didn't want to and this led to his demise, caused by Cliff.
Presumably, Clifford looked favorably upon his son, as he was the heir apparent of their family and was intended to take Cliff's place in their company one day. However, it is unknown if Clifford and Jason loved one another, or if they were at all close.
Approaching Jason's death, their relationship seemed to have soured as Jason was set to leave town, going so far as to fake his own death to be rid of his parents. The last time father and son saw one another, Jason proclaimed he wanted nothing more to do with the name or lineage of their family, including the heirloom ring he had proposed to his girlfriend, Polly Cooper with, which he threw in Cliff's face as a final rebuke.
When Clifford and his wife arrived at Sweetwater River after they were notified of their son's presumed drowning, Cliff proceeded to yell quite violently at the police as they failed to find Jason's body, despite dragging the river in search of him. Eventually, his son's body was found washed up on the shores of the river and Cliff and his wife stood aside as his corpse was taken away in a body bag.
Cliff, Penelope, and Cheryl were brought to the morgue in order to identify Jason's body. As the cloth was pulled off his head, Cheryl turned away in horror, as did Penelope, however, Cliff mutely stared at the corpse of his son.
In the days leading up to their son's memorial service, Penelope and Cliff composed a list of people they suspected could have killed their son and informed Sheriff Keller that they had all been invited to the funeral. Cliff explained that the list consisted of people that held grudges against the Blossoms, and he was sure someone in Riverdale had killed Jason.
After learning that Polly Cooper had escaped from the Sisters of Quiet Mercy group home the very same night that Jason's getaway car was set afire, the Blossoms suspected her to be Jason's killer. They organized a search of Eversgreen Forest to find her, during which they ran into the Coopers, who had a search party of their own. Cliff hypothesized that Polly had escaped once, she could have done so before on the night Jason was murdered. Later, he attended a press conference held by Alice Cooper where he was shocked to learn that Polly was pregnant with Jason's child.
At the start of maple season, in exchange for help getting into an exclusive music program, Archie was attending a banquet the Blossom's were holding as Cheryl's date. While at a fitting for a suit with Cliff's tailor, Archie wondered if, instead, Cliff could help his father's company as it was having a hard time. Cliff was impressed by Archie's loyalty towards his father as he could not imagine that Jason would have ever done the same for him.
While looking through Penelope's jewelry, Polly and Cheryl discovered the heirloom engagement ring that Jason had used to propose to Polly with. As they had believed it had burned when Jason's getaway vehicle had been set ablaze, they were suspicious as to how it got there. Later, Penelope revealed that Clifford had spoken to Jason shortly before his death, and he had told his father that he wanted nothing more to do with the name or lineage of their family, including the ring, which he threw in Cliff's face as a final rebuke. Cliff then gave the ring to his wife for safekeeping.
Following the arrest of FP Jones for Jason's murder, Penelope wept angrily and told her husband that she wanted FP dead for what he had done to her son. Unbeknownst to either that Cheryl was watching, Cliff held Penelope as she cried and promised to take care of him.