1 definition by Fat Box

A. A good-natured nickname or banter between Heterosexual bros.

B. Someone characterized by being a slutty un-thinking sex fiend with low standards, similar to someone who thinks with their dick (basically any straight male).
A: What's up you dirty Slut Muscle.

B: My friend Ben is a major slut muscle...he wants to bang all the bitches, regardless of what they look like. He's a regular bro.
by Fat Box March 8, 2012
Get the Slut Muscle mug.