Is it true men can't pick up on subtle flirting?

I F(17) have a crush on a guy I do a musical with M(19) I wanna try talk to him and stuff but I don't know what comes across as painfully obvious and what they wouldn't even pick up on. We go e each other passing glances and only talked a handful of times but I feel like with only a week until the show ends I don't know when od see him again and I don't wanna pass up the opportunity. On the other hand I don't want him to think I'm a weird bit anyways!