Am I unjustified in doing this?

Question

A friend of my girlfriend has recently been making sexual advances towards her. It began with little things, like affectionate text messages and the like, that could be construed as simply friendly, but are quite obviously meant for something more. From there it has progressed, to him telling her she should be with him, and suggesting that they should be having sex, etc. I've also heard from others that he is actively trying to break us apart. Basically, it's a lot more than just simple flirting.
My girlfriend shows me all the messages he sends, as far as I know, and she says they never hang out alone (I do trust her, but I'm not oblivious). Numerous times I've explained my disgust (I never liked this guy from the start, hes just a real back stabber kind of person), yet she continues to be friends with him. To me, it's a matter of disrespect, on her part as well as his. I feel like I shouldn't even have to ask her to stop being around him, it should've been done already.

And when I did bring it up, she agreed to not see him, but was very reluctant about the whole thing.
I understand that they have a lot of the same friends, but with the **** he is pulling, I don't see why she wants to spend anytime with him in the first place, let alone make any sort of fuss when I ask her not to see him.
I guess I'm just wondering if I'm crazy and completely unjustified in this. I'd like a second opinion before I do anything rash.
I haven't given a very detailed description of the events, and for that I apologize, but hopefully you can still help. Thanks for your time.

And when I did bring it up, she agreed to not see him, but was very reluctant about the whole thing.
I understand that they have a lot of the same friends, but with the **** he is pulling, I don't see why she wants to spend anytime with him in the first place, let alone make any sort of fuss when I ask her not to see him.
I guess I'm just wondering if I'm crazy and completely unjustified in this. I'd like a second opinion before I do anything rash.
I haven't given a very detailed description of the events, and for that I apologize, but hopefully you can still help. Thanks for your time.

Answer 1

Well, this is a type of game playing. I would let her know I felt hurt by what she was doing and is that what she wanted from you? Perhaps this is not the girl for you. If you were serious about each other, others do not matter. If someone loved me, I can't imagine they would want me to feel bad.

Answer 2

You know what? Even if he is making advances that she's never going to accept, by sending her affectionate texts, he's flattering her, making her feel wanted.. I'd wager thats why she still wants to keep him around. From the sound of it, i doubt she'd cheat on you, but i do agree that keeping him around is dangerous.. I think that, by allowing him to remain in your lives, it is only going to split you and her apart, because (even though you trust her) its horrible thinking that someone else is making advances towards your partner. I think that, rather from having it come from her (he may be able to pursuade her to carry on seeing him), you should tell him to leave her alone. Tell him it is inappropriate for him to be sending her these messages, as she is already taken. Thats all you need to do. Hopefully he will get the message.