According to Jim (2001)

S5E2 The Tale of the Tape (1)

In "The Tale of the Tape," Jim becomes anxious that Cheryl's romantic desires will heighten after his new brother-in-law, Ryan, lavishes Dana with gifts and flowers. His concerns grow when he discovers that the cherished blues tape Cheryl claims to have created for him during their courtship, which played a significant role in his feelings for her, was actually a gift from one of her former boyfriends. This revelation sends Jim into a spiral of insecurity as he grapples with the implications for his relationship with Cheryl.