For me, and I suspect a lot of socially awkward people, dealing with people face-to-face seems really traumatic. Particularly if you have massive sweating issues, and particularly if on top of that you have quite smelly sweat that smells like onion soup.
Couples are jigsaw puzzles that hang together by touching in just enough points. They're never total fits or misfits. In time, a pair invents its own commonwealth, complete with anthems, rituals, and lingos-a cult of two with fallible gods.