This kind of things happen, couples apparently like to act ridiculous, I don't know why since I never experienced it (and actually, I might never understand the"acting ridiculous" part of being in couple).
I knew a couple in uni (really objectively ugly, the guy was a fat neckbeard and the girl had a gremlin like face, I'm not even lying about this, it's just true) that used to act excessively snob, and laughed in the back of everyone (well, mostly male students) for no other reason than knowing they were single, or something like that. That was beyond my understanding since I would be personnaly more ashamed to be a part in such a funny couple rather than staying single until death. But still, apparently, being "in a couple" grants you some sovereign right to act superior for no reason ...