ok so i have this friend who i've known for quite a few years now....  

This is quite a crazy situation--I can't stand guys like that! They're too stuck up and full of themselves. It's not even comfortable for me to be around them, and I'm a guy too. I'm just watching them, they're not even doing that stuff to me! Anyway, in this situation, I'd try to talk to the girl and let her know what was going on, even if she wouldn't believe me. Hopefully, she'll see a little bit of truth in it, or at least start worrying that something isn't completely right. After that, it's really out of your hands and you can't be blamed for not trying to put a stop to it. Just try your hardest and do what you can, you can't be expected to do any more in this situation.

This is probably one of those worst case scenarios that usually never happen to anybody. Someone you care about falling into the hands of someone who doesn't care for them and will only hurt them or cause them pain in the end.

I was thinking about this and I have a friend like yours and I sorta set the situation in my head with my current girl friend that I care for very much. What I came up with was that I HATE it. I wouldn't let my friend do that to her. As my friend I'll put up with him being a player to every girl there and just sit back and smile at whatever accomplishment he's done this weekend but if he went after the one girl that I like for the most...I just can't let that happen. I would talk to this girl tell her that that my friend is no good for you and is only using you and only has one thing on his mind. I would know since I'm his friend and the only reason that I would be telling this girl of all the other girls he's been with is because I care for this girl more than my friend does. I'd try my very best to convince the girl I like to know whats going on and understand what I'm feeling.

As for my friend I'd tell him that he should let her go and go find some other girl that if he could just leave this one girl alone. Maybe talking to him this way he might understand that I really like this girl and as a friend he will back off and if not then he would be to bad of a person for me that I wouldn't want to know.

I don't know about you since you may be different, but I'd do anything to make things right. I'll give it everything I've got to make sure she doesn't end up like every other girl my friend throws away. Anyway I've got a few scenarios as to what could happen and idk how strong the relationships are here so I just put one or two of mine to give myself a better idea......sorry if this a bit long lol.

I mean, i know its a hard situation for you, but if ur friends with this girl at all, try to explain to her how hard it is that you're saying this about ur best mate, but that he is trying to sleep with her etc etc. I think at first she will be a bit shocked and might deny it, but I think in her head it will start to make sense, that he has been pressuring her etc. Then she can make a better decision. Hopefully she leaves on her own, and so you can save both the girl and the relationship to your friend. But seriously yeah, its very hard to be friends with people who you don't respect.