What did Rick think BP was going to say?

At the end of the episode Rickternal Friendshine of the Spotless Mort we see the following interaction

"Rick, I do not like to pull threads, it is a disruptive and feline activity, but I must ask-"

Rick interrupts, like he knows what BP is going to say "It's fine, you don't have to!"

BP continues "was there really a second in there where you knew about my child and chose not to tell me out of fear I would become too busy child rearing to hang out"

Cut to Rick looking surprised, and saying "Oh, uh, weird way to thank me for discovering your kid!"

Whatever he thought Bp was going to say, we get the impression Rick thought wrong.