As with all things, it’s a matter of framing.
The Leisure Suit Larry series is (obviously) a work of fiction, and one written by men. It’s also a comedy. And yes, we’re supposed to be laughing at Larry and the situations he gets himself into, but this is of course filtered through what the writers thought was funny back in the 80s and 90s.
The punchline of this situation is that in his quest to get laid Larry has done something framed as gross, disgusting, and beyond the pale: kissed another man. It’s not about ethics in real world hookups but about the framing of homosexuality and gender nonconformity as a gross thing and a punchline, and (to a lesser degree) of casting trans women and gay men as predators trying to trick straight men into bed. Which is, as @Draconis mentioned, an attitude that has terrible real world consequences.