Guts or balls.

There is a medical distinction. We've all heard about people having guts
or balls, but do you really know the difference between them? In an
effort to keep you informed, the definitions are listed below:

GUTS - Is arriving home late after a night out with the guys, being met
by your wife with a broom, and having the guts to ask: 'Are you still
cleaning, or are you flying somewhere?'

BALLS - Is coming home late after a night out with the guys, smelling of
perfume and beer, lipstick on your collar, slapping your wife on the butt
and having the balls to say: You're next, Chubby.'