Please cite a reference or two supporting your contention that monogamous heterosexuals are deviant and outside the norm.
You could try Kinsey survey—— 12% of males report having only one sexual partner in their lifetime. And I suppose, being Kinsey, they included homosexuals, so the number for Heteros has got to be even lower. That’s deviant by definition, but I was only kidding, though in a factual way.