Slutty behavior is an Urban word for showing improper behavior (A behavior not accepted morally or ethically.)
-E.g- A married women flirting with other people.

Slutty behavior does not always mean having sexual activities with many people. It can be anything improper that gives another person wrong impression about your character.

A man who messes around with other men, but no one would ever know by looking or talking to him. Used by gay black men to identify masculine gay men or DL Brothas.