Not true - the crux of the joke is not that Andy is supposedly gay. The crux of the joke is that you wonder if the "Andy" represented in the joke is actually gay and then when you get to the punchline you realize that he's actually not gay, not a prostitute, and he has to be held down for the transaction to be completed. It's actually a joke about male rape, which is something that everyone enjoys laughing about. Don't we? Now you get the joke, and what also lies behind it. What? What lies behind it? Cultural commentary. Andy is wrong - he is uncomfortable by how Norm stigmatized him personally with this joke, and now he tries to make that outrage related to homophobia instead of what it really was - Norm was bullying Andy in that clip. And, yes, that's not cool - generated laughs, but it hurt his feelings. That's what this is about.