We all know one.

The friend, cousin, dentist or colleague who -- despite voicing attraction to the opposite sex, owning the world's largest collection of straight porn, being married with kids, what have you -- everyone thinks is gay.

We now know what to call these "don't judge a book by its cover"-types: strays! (Thanks to Buzzfeed for disseminating this term and Detail's Mike Albo for coining it.)

According to Albo, there is some scientific evidence behind our gaydar signaling whether a man complimenting us on our tight vintage T-shirt at a bar means "I wonder how I'd look in that" or "I wonder how you look under that." Voice and body language are fairly dependable indicators.

Style, apparently, is not. Metrosexuals should be evidence enough that looking gay doesn't signify homosexuality. The thing about strays is that, unlike closeted gays, they really are actually straight. We can imagine this consistent misjudgment being quite exasperating for said strays. Perhaps they should carry around copies of brain scans, proving their lobe size and neural activity to be like those of their own sex, as recent research shows gay brains act like the brains of the opposite sex.

Check out the Details slideshow of famous strays, from SpongeBob SquarePants, Russell Simmons and Tom Cruise to John Travolta (we're not totally convinced he belongs in the category, to be honest, which makes him either a very-well-closeted gay or an extremely frustrated stray).