Bobhot is when Bob, who thinks he is not hot according to the general standard looks hot. He will admit to looking better than usual but still not quite up with whomever he is comparing himself to. Therefore to boost his self-esteem without making him uncomfortable, we use the term bobhot.
When Bob switches from his usual look of cargo shorts, gym shoes and a random t-shirt to wearing a tuxedo or something of that nature. In recent times, Bob has put himself into a new state of bobhot by ridding himself of the combover he sported since he had enough hair to do it and moving into the late '90s with some sort of spiky thing.