Guts or balls?

We've all heard about people having guts or balls, but, do you
REALLY know the difference between them?
There is a medical distinction, but there is no difference in the outcome.

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?

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.