Why are you so bothered by this? You are aware that this girl probably had other guys before you and she will after you. Just ignore and game on. No need blow up a minor detail. If she doesn't bring it up, then you don't bring it up. If she does bring it up, just say "oh, you guys would be cute together" or some shit like that. I remember my ex tried to get back at me by hooking up with one of my roommates(making out) and when she told me, I shrugged it off. Lol, the look on her face was priceless.

Just keep going. It still too early to to tell what is going on. If anything, if your friend is a good guy, he will tell you if the girl contacts him again or he will cease pursuing this girl if he only wants to get his dick wet. Once again, don't blow it out of proportion.

I guess you are right. This happened before our date. She was ok to do what she wanted. And she didn't have to tell me anything. The fact that she did shows she's honest and she didn't want me to hear it from someone else, namely x. The problem is, I am not sure x will back off completely, I don't think he can help himself if she continues to text him. Me and x get along ok but we've only been friends for less than 2 months. I don't know what he is like as a a person all that much. He is definitely a player, we are polar opposites - at least for this moment in time.