[PSY]

If you're still entertaining the idea of dating your first girlfriend, then you shouldn't be with your current girlfriend. Seriously. When you're with someone, it's natural to wonder about ex-girlfriends from time to time... but if you're wondering whether or not you should ask her out again, then it shows you're not fully invested in your current relationship. That's not fair to your current girlfriend, and you need to either figure things out (quickly), or end things with your current girlfriend. It's going to hurt her, but it's going to hurt her a lot more if you string her along for a few more months, then dump her to give things with your ex-girlfriend another shot.