What will happen to the gas in a perfume bottle when perfume bottle is open?

I don't think any universal laws like gravity or friction effect gases so my bet would be that some would stay in an some would go out. Only way to know for sure is to open one. well wait, is it a liqiud perfume? cuz then they're not spraying out gases its a mist of liquid in which gas the perfume would stay in the bottle.