Most Helpful Guy
As others said, don't think too much into it. First, it's meaningless cause the past is the past. Second, it's just a birthday. You're one year older. Happy birthday simply means that you're being nice and telling someone to have a good day, nothing more. Third, it's a shame that we, as a society, can't act or say something nice to the opposite sex without them thinking that we have alternative motives. Just accept the happy birthday, thank him, and move on.