I was wondering how you know if your friend's boyfriend has a crush on you?
If I suspect he does I'm ending the friendship,I don't want to come between them.

Ask him.

That's really the only way to know for sure.

Good for you to take the higher ground as well!
Smart and cool always beats out dumb and selfish :)

There's no way to know without asking.

However, maybe you should consider telling your friend first about your suspicions, so that she doesn't stick around much longer with a sleezeball.