Rosequartz, apologies if I've misunderstood your post, but I read it to say you knew a gay couple, one of whom was behaving in a "not nice" manner, and that his partner is putting up with it placidly. If you meant a hetrosexual married couple, sorry for misunderstanding.
Your point confirms those made by many posters, that gay couples are like all couples, some have good relationships, others not so good, and some are abusive relationships. It is not uncommon for the victim in these situations to appear placid. It's often linked to their fear of winding up their partner and a means of avoiding conflict. I'm not sure about the up to date figures, but when I was working, the research suggested women in abusive relationships may leave and reconcile as many at 20 plus times, before finally getting the courage to leave.