Denise was a rich woman Jack met on a date set up by Larry.
Unfortunately, Denise is controlling and tries to make Jack into what she wants before marrying him. Janet and Terri panic, but can't convince Jack that Denise is wrong for him. In desperation, Janet plays a "game" with Jack's pants. Denise shows up and misinterprets what's going on, and accuses Jack of lying and tells him he'll be put on a short leash after they're married. Jack says a "permanent" goodbye to Denise, and his roommates console him.