Panel 1: Since the poor girl he fixated on wants to date someone she actually likes, Gordon decides that he isn't going to the school dance. Mike reminds him that since it's a school function, that option is off the table.
Panel 2: When Gordon asks "WHAT FOR?", Mike sets up the stupid punchline by telling them that he guesses that they consider it a learning experience.
Panel 3: Since all Gordon thinks he's learning is that girls are horrible people who date people who aren't him, he asks Mike what they're supposed to learn by going to a school dance.
Panel 4: Mike says "How to handle humiliation" because it's someone else's fault that his life is a fucking mess too.
Summary: Michael simply will not admit that most of why he's seen as "that dumbass who they used to be able to talk into doing anything" is that he's a dumbass who can be talked into anything. He can't admit that Martha is the injured party in their relationship because that would mean that he's the one doing the injuring. As we'll see Monday, he can't admit that his ludicrous assumption that he's this cool guy having his rightful attention stolen from him is why he repels all but the desperate, spineless and stupid.