Let’s assume OOP is an openly gay dude. That’s why he has a profile pic on grindr (implied). The dude who’s hounding him doesn’t.

Suppose OP is roommates with a woman.

Suppose that woman is in a relationship with a guy who’s bi/curious/closeted and is hounding OOP because he’s seen him while visiting her.

That would make sense.

But I think it’s just a punchline