Yes, physical attraction can develop where it wasn't obvious before. For me, often a dream about a casual acquaintance will trigger attraction that I wasn't aware of before. Maybe, you could try asking for a dream about him, before you fall asleep, and see what develops. One thing that you could do that doesn't risk hurting a nice guy, is to try fantasizing about him in that way, and see how it feels. If it doesn't work, no harm has been done!
