Straidar

Kind of like gaydar except instead of being able to tell if somebody is gay, straidar tells you that he/she straight even if he/she acts, looks, or talks as though he/she is gay.

It's the Heterosexual spidey-sense

Bob: Dude it seems like every time i'm near you my gaydar goes of the charts.

Rob: Don't worry Bob that's probably just your straidar.