Introducing Dr Love, who solves your relationship riddles in a confusing digital age

My girlfriend and I have been arguing a lot lately, about things that don't really seem very important at all. I don't know if she's doing this to end our relationship, because I get that feeling at times. I have asked her repeatedly why these little things are beginning to upset her now, when they never did before, but this only makes her start another argument. It's becoming tiring for me because I no longer look forward to meeting her. I'm afraid this will end up pushing me away, whether she wants to or not. I don't want our relationship to end though. What should I do?

If you believe this is worth fighting for, you should. Your girlfriend may have a different point of view though, not just about the state of your relationship but about the issues you deem minor. If she doesn't want to talk about them, I suggest you talk about other things. Also consider giving her a break every now and again, so you don't meet as often as you currently do. Maybe time away from you may help her re-evaluate the relationship and give you time to understand her better too.
For now, try and be a little more understanding, until she is comfortable enough to open up and tell you why things that didn't affect her before are bothering her now. Relationships evolve; this is just part of the process.

Is it normal for someone to date three women at the same time and claim to be good friends with them all? I like this guy a lot, but he is open about the fact that he goes out with two other women and doesn't want to commit to any one of us. I want him to be with me alone, but that doesn't seem like a possibility. Should I continue dating him?

An open relationship may seem interesting at first, but soon becomes difficult to manage. I suggest you always put yourself first and don't settle for anything less.