Rold,

You're in a bit of a tough one, with your "love interest" being someone you work with. There's almost sure to be trouble, any way it works.

But, as others have said, he *could* be misinterpreting your interest in him as that of you being nice and friendly. Does he know you're bi? Are you out at work? It never ceases to amaze me how dense (some) straights can be when it comes to same-sex romantic interest!

Anyway, as he is your *assistant*, and if you do express your interest in him, he *could* misinterpret that, or make a case, for sexual harassment. He probably wouldn't get a LONG way with it, but you might have to look for a new job, if you're not out at work. If it does work out great, there will be a problem with working *that* closely with a love-interest or partner. Or, it can get nasty if or when you break up.

As Teddy Bear said, HOW does he know you havve a crush on him? Have you told him in so many words? If not, it could be heterosexual denseness. And... he MIGHT have left for some reason besides jealousy.