Top definition
That look on a girls face when you cum on her tits. Not a full on grin, but just a subtle smile that you aren't sure what it means, but you think she's enjoying it.
Sherry gave me her Mona Lisa Smile when I came all over her tits, but it went away after my buddy Tim nutted all over her face.
by Ed Rooney Jr July 18, 2016
Happy St. Patties Day!
After you cum you take the residual cum on the tip of your penis and apply it like lipstick to your partner's lips.
"Wow, Sam's lips look really shiny," Friend 1.
Friend 2, "Yeah, I just gave her a Mona Lisa Smile."
by The Drs September 02, 2010
Happy St. Patties Day!