Such actions may include:
-Flashing her business in public
-Hooking up with other guys and girls while she has a boyfriend
-Lying to her boyfriend
On top of it all, she'll tend to claim that she's a good girlfriend and that she doesn't cheat.
Guy 2: Whoa! Seriously?!
Guy 1:Yeah...I'm giving her another chance though.
Guy 2: Why?! That's not a girlfriend, that's a Snooki!