I want to flirt with a girl while in a relationship
Why would you flirt with someone while in a relationship?
I'd like to meet some new girls.
Partner's in a relationship are expected to be faithful to one another. If you flirt with another girl outside of your relationship you'll be seen as a cheater. Your current gf could get upset and break off the relationship.
I'm just gonna act like I'm not in a relationship.
That's terrible, you should just be faithful to your girlfriend and not cheat at all. Or at least break up with her first before you start sleeping with others.