What do I do if he loves both me and her?

I'm in the exact situation.I care deeply for the one I 've known for years yet there's someone I care just as much about.Honestly there's nothing you can do because it's up to him.There's nothing you can do or say cause he's going to listen to what his heart is telling him.If you really love him all you can do is sit back and wait and if your not the one he picks don't be hard on yourself.Don't let him drag this on for to long cause it justs makes it worse.Trust me I know.Really you should really look at the whole situation.How long have u known him and how long have u loved him.Do u think maybe there's a chance it's just infatuation?You really have to sit back and think about those things cause u might be wasteing your time.