After being challenged to a basketball game by the Harlem Globetrotters, the Professor grows some mutant superman to play against them. He harvests some chronitons to accelerate their growth. After which times starts leaping forward at random moments in time.
During the time jumps we see Fry and Leela get married. But Fry cannot remember what act caused the change in Leela's mind about their relationship. Fry desperately tries to discover what great thing he did to win her heart only to see that destroyed before his very eyes.
Overall this is a very special episode, another hint towards the fact that Leela holds feelings for Fry.