I've changed my mind, I would say go for it man. I mean hang out with her for a bit first and then ask, but I would say go for it. The only way that you're going to gain the confidence and experience to do this in the future is by acting now. I wish I would have learnt that lesson earlier then 17, but my life has been so much better just because I've been going for stuff. You know every guy who radiates confidence and has no problem talking to girls? They've all been through countless awkward situations to get to that point. My point is go for it, she may say yes and she may say no, but either way you'll gain some experience for it and the next time this happens it won't be so awkward.
I just think it's a lost cause. *shrugs*. He doesn't have the confidence, and it's going to show when he approaches her. And nothing looks more painful than watching a no-confidence guy get up the courage to tell a girl he likes her. It's like watching a train wreck. And odds are, if hes on a time limit like, shes moving or something. It's STUPID to tell her. All it's going to do is make her (probably already sad and uncomfortable trip) more uncomfortable and long.
It's a lot less painless to see a 14 or 15 year old kid do it then a grown man. The only reason this guy's nervous is because he has very little experience with it. Everyone develops socially at different stages, but without actually doing stuff, you'll get nowhere. I have friends who are 18 and are scared [censored]less to approach a girl in the bar, much less in class or somewhere like that, and its only because they're too shy to act on anything.