[quote=@MoiraEl]
When people use "homosexual" instead of gay. Like, you don't sound smarter when you use it and the word "homosexual" has some deep-rooted negative connotations with general ick. (See: the holocaust, conversion therapy)
[/quote]

But homosexual is the scientific term. If someone uses it in casual conversation like "oh hey he's a homosexual" I get you, but when it's appropriate there's nothing wrong with it imo.