"I think being asked to make more noise is a first."

Wow, tense... Popp has the social skills to tell when someone really doesn't like something, if not the experience to guess why in this case. He's sensitive and self-centered, of course he assumes it's about him in specific. Does Ivan not actually think of him as a friend?

For all that he's annoying on purpose sometimes, it's not actually fun if you're not openly yelling at each other. He lets go once he's sure he can do that without falling over - nope, he can't after all, he kind of. Crumples downwards, clutching his side. This is very embarrassing.