A Non-Straight Gangbang is what happens when the girl leaves the gangbang early or doesn't even bother to show up. Your normal everyday gangbang becomes a non-straight gangbang when the guys who remain want to continue the "festivities." Hilarity ensues during the process of selecting the person who is the new one to be gangbanged.
Aging porn star Amber Waves left her gangbang wayyy to early and the remaining guys decided to have a non-straight gangbang.