It is a phrase used in converstion between friends that's a quick and discrete way to tell them whatever is said is not to go farther than you all.
Alice is talking with her girlfriend about something she wants no one else to know. She then tells her and then says " stays in vegas. "
by orientallily October 30, 2006
Get the stays in vegas mug.
It happened. It only happened there. And it happened far enough away to have any negative effect on the "the here and now".
And anyone who wasn't there at the time need not know about it.
So stfu about it, and move on. But keep the memories. ;)
Dane Cook's intro to a recent show in Las Vegas:

"...great to be back here in Vegas....you know how they say 'what happens in Vegas stays in Vegas'....? Well I have a new saying....if it happens in Vegas, and I see it....I'm fuckin' telling EVERYBODY!!"
by Mister B. November 18, 2006
Get the what happens in Vegas stays in Vegas mug.
What Happens In Vegas, Stays In Vegas
('Cept Herpes, that shit stays with you for life)
Sarah: I can't remember, but I think I lost my v-card to someone last night in Vegas...

Best friend Nick, who was the one that she last her v-card to: Well honey, what happens in vegas stays in vegas. No worries.
by AddictedToGrunge July 7, 2009
Get the What Happens In Vegas Stays In Vegas mug.