Mines a bit unreliable..lol .. I mistakenly assumed two guys drinking out together were a couple .. I'd had a few glasses of wine and made a comment on how happy they looked together.... they were straight mates .. oops... cue red faces and embarrassing silence ...taught me not to presume and keep my mouth shut 🤐 😃X
I totally think a gaydar exists...but I would say that it's more just your awareness of people. Watching how girls interact with girls, guys with guys, etc. People have tells, and if you're perceptive, you can pick up on them. Then, of course, there's obvious things like the stereotypical way someone dresses, wears their hair, or something of that sort that can also give you hints about someone's sexuality.