Genuinely funny, but also genuinely homophobic [confused gay laugh]
More seriously, though: If it's only funny because it features two persons of the same sex, it's homophobic.
Imagine the shtick with a man and a woman : it's not as fun or not even fun? Yeah, that's because the whole point is the fact that it's happening between two males. Homophobia IS the point, and it's not because the comic features diverse people that it's not making an homophobic point.
Whoever the author is, they're forgiven because it was funny, but I encourage them to question their work.