The ability for some to determine, by some supernatural force, whether another individual has performed a sexual act recently.
Chloe used her sexth sense to determine that Bobby had, in fact, been sleeping around.
by DDDSRT October 24, 2010
It's a kind of intuition linked to sexual matters it makes the person guess people's sexual capacities among other things.
My sexth sense tells me he's got a tiny penis!
by I_zzi April 16, 2014