I've been dating a man for a year. We started out as just friends going out and doing things together on the weekends, but it's recently become more serious. He has told me he wants to be exclusive and wants to start spending nights together and taking vacations together. It all sounds very promising.

Last weekend, we went out to hear a band at a local bar. While there, he spotted a woman who he said is on his Facebook, but he's never met her in person before. As for me, I don't add people who I don't know on my Facebook, but apparently he does. He left our table and went over to introduce himself. When he came back, I asked him what her name was. He told me. I still found it strange that he had a total stranger on his Facebook, and then left our table to go introduce himself, but let it slide, because we were supposed to be having fun.

Then I went home. I decided to look her up on Facebook. She has some of her posts blocked, as we are not friends, but every single one of her pictures, he has "liked." In fact, she just posted one today, and once again, he was quick to "like" it.

It bothers me. It bothers me that he had a total stranger on his Facebook. It bothers me that he left our table to go introduce himself. It bothers me that he "likes" her pictures, even the most recent one. Having dated more than one unfaithful man, I hesitate with the whole, "Why don't you talk to him about it, ask him," because that usually leads to defensiveness and shut down.

Has anyone else had experience with this kind of behavior? Is it a red flag, or am I being too sensitive? Is there a way to handle this so that I can get the answers I need?