According to Jim Recap: Father-Daughter Dance
Jim is troubled because Ruby doesn't want to give him a kiss goodbye at school, but he hasn't seen anything yet. She doesn't want to listen to him at home either, but she's still just getting started. Cheryl advises him to back off, but he insists that he knows what's best, so he does it his way.
When Ruby wants to sit at the other end of the table (and put Dana next to Jim, he takes it in stride. When Ruby asks Andy to take her to the Father-Daughter dance at school, Jim accepts it, but in reality he's the one that's hurting. Naturally, Ruby is too, but she isn't going to show it.
After talking to Cheryl, he realizes that Ruby needs him to show some strength, but give her the space she needs to start growing. So he dons his suit and meets her at the dance, where she shows him that she really does love him. Of course, after seeing Andy dance, that's not a hard thing to do.
