I've been on the opposite side of the coin. Last year I was made aware that one of my (college) students had a crush on me. My case is a little different because at the time I was already seeing someone, but same basic idea. If you're already talking to him, and he seems interested, I don't see any reason not to pursue it... BUT I would wait until AFTER graduation. Teachers can lose their jobs and their licenses in most places if there is any evidence that they've had an "inappropriate relationship" with a student in their class. Once you're out, though, you're good.
