What happened with Kathy and Biff?

[tammyy2j]

I remember they were a couple before but when they returned for Seth's funeral, did they even interact. I know Kathy went to Australia with Alice but did she cheat on Biff with pschyo Graham or what. Can some please help.

[Chloe O'brien]

I i can remember right they got as far as the alter one of them decided they did not want to get married. i know that biff bought seth's and betty's house for them but i'm not sure where he went to live once kathy went to austraila

[samantha nixon]

one of them stood the other one up at the altar i think biff left kathy standing there