You couldn’t draw this up any better if you were Steven Spielberg.
Going “commando” is one of those actions you definitely want to keep private, unless your significant other is cool and on-board with that decision. So when that privacy is threatened, you can imagine the horror one must feel from having the people get a glimpse at their “intimates.” That horror produces actions, like this guy, who straddled his girlfriend to cover up her cookies.
If he were that desperate to keep her pants above her waist, he would have let go of the ride. Because that certainly didn’t look like he was trying to help the situation—that looked more like a show.