What should I do if a guy I really like is dating someone?
Move on and find someone else. There are plenty of other guys out there :)
Deal with it. It sounds like you should've when you could've.
move on, his already dating something you can't break up their relationship. unless they break up, just start talking to him, but don't rush him.
wait they won't last long
Move on! And if u like him like ALOT try impressing him.
Leave them alone. If you and him are meant to be together. It will all work out in time. If you press the issue you could lose him forever