[Northern Monkey]

So i was just watching this video of this gay guy coming out to his Conservative Christian Dad.

Youtube video

You could tell how hard it was for the lad and his dad actually took it really well.His dad said he'd 'had his suspicions' and I lol'd at that because it's blatantly obvious that he's gay.He's not acting particularly camp or extrovert but he has all the mannerisms that you expect and the not so deep voice.
But then that got me thinking.Like at a guess 95% of the time you can tell when someone is gay.Not always but i'm pretty confident that i can usually always tell.Infact I don't think i've ever been wrong if i'm being honest.

So what is it that makes it so obvious most of the time?
I mean just because someone is attracted to the same sex shouldn't necessarily be coupled with a stereotype.But it is and it's not just a made up stereotype.It's actually there.
Now I don't believe all gays put it on.I know some flaunt it more but i think underneath that these traits would still be there.Just not so overtly.
Is it a gene that gives these traits along with the same sex attraction?
Or is it maybe less testosterone and more estrogen?
Or something else?
Anyone studied this stuff?