I asked this guy out for my best friend even though I liked him too. I guess because I didn't think he would say yes. Now they're dating and I feel dumb. I told her I was jealous but she didn't care I guess because all she did was say wow and pretend like I didn't say anything for the rest of the day.

What could she say? I am sure it put her in an awkward spot since you got them together, she didn't know you liked him and now she isn't about to give him up. Even if she did that doesn't mean he would come running to your arms.

Even though it sucks, you made your decision when you asked him out for her that you weren't going to make a move yourself. I would say that you should try to move on. If you absolutely have to tell him/her how you feel, leave it at that and don't do anything to try to compromise their relationship.. That's a damn good way to lose friends.

This sounds like a severely adolescent situation, and the two people you are talking about sound pretty immature at that. Find someone else, and stop doing your friends dirtywork. If they like someone, they can handle the situation... it isn't your job.