Right. Buster avoids Lucille (misses the surprise dinner party because he was avoiding her), goes to Lucille to try to tell her she's got the wrong idea, ends up kissing her, then the jumping window scene:
Lucille 2: Buster, do you remember when we were kissing last night?
Buster: It was a wild, wild ride. But is this something we can do? Is this something society will allow?
Lucille 2: I don’t care what other people think. My God, for the first time in years, I felt like I was standing on solid ground.
Buster: You know, my panic attacks have decreased. I feel confident. I’m feeling proud even.
Buster: I mean, for the first time in my life...
Gasping. (jumps through window)
Lucille 2: I’ll call Dr. Miller.
Sounds like a conversation at the beginning of their relationship. Compare with narrator description early in the previous episode: "In God We Trust"
Narrator: This concerned Buster, as he’d been secretly dating his mother’s best friend and chief social rival, Lucille Austero.