tspies-Decisions in Marriage

As I listened to the discussion on Tuesday all I could think of was the movie I saw on Spring Break. "I Love You, Man." (I won't spoil the movie). One of the couples in the movie had established a terrible relationship based on the principle of least interest and and the coercive influence. The wife REALLY wanted/needed her husband to invite a friend's fiance over to play poker. The husband didn't want the fiance came over but his wife bribed him with sex, and he decided what outfit she had to dress in. Everyone in the theather laughed at such control, but the wierd thing is that this seems to happen in too many relationships. I am not sure how the wife in the movie was ever happy with this relationship?! I have never really been in a long-term relationship but still seem to know what I want (and it doesn't include this) Can relationships last on the basis on unequal decision making and power?! It seems to me as if the relationship would never be 50/50 in happiness but more like 90/10.