According to Jim Recap: Sympathy from the Devlins
Cheryl thinks that Jim, Andy and Dana all have strange superstitions when they watch sports (in this case, basketball). They even make her deliver her "comeback" sandwiches walking backwards because she did it once and the Bulls won. When their old neighbors, the Devlins (Tim Bagley and Cynthia Stevenson).
Naturally, Jim goes a bit overboard and invites the Devlins, who have a habit of calling everything by cutesy names, to every single game for the next few days. Cheryl calls him on it, saying he has a problem and says that he needs to watch the next few games without them. As soon as the Bulls lose, the Devlins become necessary, so Jim heads to a hotel in order to watch the game with them without Cheryl finding out.
When they ask what is going on, Jim tells the Devlins that he and Cheryl have split up. While that probably isn't a good idea, it gets worse when they try and set Cheryl up with someone, and it gets even worse (yes, that is possible) when Jim says that it's okay for Cheryl to go out with him - as long as he can watch the game with the Devlins.
This is also one of the episodes (which are growing at a disturbing rate) that has Andy in bikini briefs - he rips off his pants near the end to show that he can be a good luck charm, just like Tim Devlin, who did it earlier in the show (the Bulls win, so he's allowed to stay in them).
