Jon, from the early scenes of this video it looks like you have plenty of privacy with the majority of passengers in front of you. Let me ask you if you could have gotten away with taking your pants fully down for more freedom, and therefore more sexual pleasure. Greater still from the adrenaline rush of having your pants down. I'd like to know, since that's what I'd be doing if at all possible.
Just seeing how empty the entire mid-back of the bus was, I very definitely would have done this, except I would have had my pants and underwear completely down and legs apart for even greater pleasure. Also I would have ejaculated that sperm into a handy paper towel, preventing a mess, and making it easy to wipe my penis.