Guy 2: She's a mona lisa, bro.
Guy 1: Well, there's definitely a special place in hell for her ex boyfriends.
2. a girl whose emotions are absolutely unreadable. These girls are the hardest types to understand.
My girlfriend is such a Mona Lisa. I can't ever tell whether she wants to shoot me or do me.
To Mona Lisa it, or "pull off a Mona Lisa," if you will, is to take a dump in such a way, that when you wipe there is no crap on the exterior of the anus. Thus, after the first wipe, the toilet paper remains pristine white, pink, or whatever the original color. Congratulations, you've painted the perfect picture on the toilet paper: You just mona lisa'd it.