Can someone explain the sudden appearance and marriage to Ron Cadillac?

I'm rewatching again, got to season 4 when they do the Bob's cross over, and Mallory is just married now. Archer stole the limo and rode off during the wedding. And while in all the early seasons, Mallory is literally throwing herself at any rich guy near her age group, it does seem like there was no dating or anything in the show. Like they needed a way to make the Bob's crossover happen, and made up a new story/character to make it happen. Would have loved to have seen like a 1 or 2 episode thing like Heart of Archness between seasons to set this up......