Well, that could either be the trucker's ending, or the kiss with Phil.
I suspect is the former. If that's the case, then you should use the cleaner stall at the start of the game, and try to hitch a ride with him later on.
Got it! :D There's 4 more empty slots in the very last page of the Gallery - am I missing a route, or is that just blank, in case you ever add another route? ;)