When a guy isn't with his girlfriend, and he thinks that everyone around him is pretty because he has temp. blindness.
Guys with this syndrome tend to cheat on their girlfriends vigorously and with various ugly girls, making their girlfriends feel like they're the ugly ones. This syndrome not only effects the guy's friend's views on him because at any given chance he hooks up with nasty smuts and it makes him look pathetic and desperate, but heavily effects the girlfriend..making them insanely jealous of everyone, even the fattest and ugliest of girls, since the boyfriend is already known to hook up with the fattest and ugliest of girls.
"Is he hooking up with Patty? Does he know Patty is actually a guy?"
"I think he has NGAB syndrome.."
"oh, that explains A LOT."