Wow, That sounds awful. Have you ever tried having like a serious chat with him and no one like pushing or telling him to say things. I'm sure if you have a talk with him you should be able to sort something out. The only problem you'll have is that his out with your best friend and he can't exactly finish her just to be back with you. It's going to be a hard thing but I suppose it's duelable. Depends what Kenyon thinks about the whole situation.
If you do get a serious talk with him you should talk bout what's happened and what it's putting you through and how you feel about the situation. I'm sure if his a decent guy (As you claim) he should do something about it. Although it may not be what you want. If he was single it'd be easier, but with him having another girlfriend; It'll be hard.
I'm sure something good will come out of the serious chat, IF you can get one without any interuptions.
Good Luck
