Maybe he has found someone else to crush on. It happens.
What possible reasons are there for a guy to stop crushing on a girl?
The reasons are legion. If I was crushing on a girl who unexpectedly lit up a cigarette I'd back off, but that's just me.
The fastest un-crush I ever witnessed was in an episode of NCIS when Special Agent Tony DiNozzo, a boy in men's clothing who hits on every woman he meets, arranged a date with a pretty forest ranger. But when she reached up for her mobile phone he saw that she had long, dark hair in her armpits and his libido went into a panicked reverse.
Did he witness you "breaking wind" or picking your nose? Tell him he shouldn't be so quirky!
@smiley, loool!
He may like another girl.