A hand in poker which comprises of a Jack and a King of different suits. When combined the hand could be described as being Jack-King-Offsuit, often abbreviated to jack-king-off. This sounds like jacking off, a common past time of bachelors supposedly.
The act of grabbing a woman's breast, instead of the usual handshake. Then as she raises her hand to slap you in the facehigh five her. Walk away like a fucking badass.
Joe: I got a restraining order filed against me.
Bob: Why?!
Joe: I gave a bachelor's handshake at the club last night.
Bob: Woah! You're such a badass