I got back together with my girlfriend

Makes sense to feel insecure. She tried to get with a better man in her eyes and he had other ideas. He was probably the type of guy who didn't need to commit to any one chick and doesn't want someone elses baggage. Oh he'll fuck her, so much she sees stars afterwards, but that doesn't mean he wants to put up with her bullshit. Thats your job bro

Hey just be glad you've got a woman. Is she cute?

Nice douchebag response, HOG.

The truth is you don't have enough information to know exactly what's going on with your girlfriend, Wally. Yes, it's possible that she was considering dating another person, but it's also possible that she went out with someone else only to realize that you're the better man and that leaving you was a mistake. It's also possible that the breakup was caused by a completely different reason. Again, not enough info.

Second, you SHOULD mind being someone's second choice. If you don't think more of yourself, others won't either. The most important kind of respect is self-respect. It all starts from within. And the fact that she's with you disproves your statement that you're not the kind of person any woman would want to be with. Apparently she wanted to be with you before and is still with you.

And finally, the best way to find out what's really going on is to talk to your girlfriend. I mean really talk to her, as in, a heart-to-heart talk. Try not to put her on the defensive and do try to see things from her point of view. In other words, try to empathize with her.

And during this deep conversation, I recommend politely (and I really do mean politely) let her know that being the backup is not acceptable to you. Of course, that's just my opinion because I would rather be single than be treated like a doormat. If being with someone is more important to you than being treated with respect, than disregard my last piece of advice.

Do you know that she broke up with you because she was interested in someone else?

Maybe she felt unsure about your relationship and thought a break would help her clear her mind, she realized she loves you and came back?

Thank you for the replies, everyone. I really don't know what to do about her.

There definitely is a lack of trust in our relationship, but I don't know if it's justified. I am a very paranoid person and think people are always out to get me, so I don't know if my current lack of trust is just a manifestation of my innate paranoia or if it is reasonable.

You are so consistently harsh on yourself that you make it so. You have told the universe that you think you don't deserve to be happy, and insist on making it true.

Just try for once being glad for the pleasant companionship of the present moment, without worrying if she will be there tomorrow. And I hope you check back out of curiosity now that you are 'on vacation' from here and discover that it was nice just being there, in the land of 'just for today'.