Most Helpful Guy
Really, what do you do? You did the right, just walk away. Not worth it to get in someones face over that. For me, I would be proud that my partner is attractive that much to gain attention from others. I also know she is mine and I have nothing to worry about. It happens more than you think. Just be proud of him and be the best girlfriend you can be and appreciate what you have.
Most Helpful Girl
I don't mind anyone flirting with him. What matters to me is his reaction to that and if he does anything to avoid/reject/warn them not flirt or just leave the place like your boyfriend. The first (them flirting) can't be controlled, the second (him doing something about it/reacting in a way that doesn't encourage them to flirt more) can.