When people say "I think he's gay" when discussing a man with stereotypical "gay male" features

And I'm just like "Was he involving in sexual intercourse with another man when you saw him? No? Didn't think so. Did he tell you he was interested in men? Then how the fuck do you know then?" I don't behave the way I do because I'm straight, I behave the way I do because of how I was raised, and because of the environments that have surrounded me all my life thus far. The fact that I am sexually and romantically interested in women takes no part in what I wear in the morning, or in how I decide to brush my teeth. So let's stop acting like there's a preset of behaviors that go with a sexuality, or gender, etc.