Haven't I heard somewhere that the brain is really the main "sex organ?"
Being mentally sane then, having a great and caring and moral and intelligent personality, would seem to be far more relevant to relationships and sex, than actual physical "endowments." Although obviously being more "endowed," seems to help some.
Being some "circus freak," in being "unusually endowed," probably isn't going to help form lasting relationships, all that much.
While some people may think it's their little head that decides when to have sex, obviously that isn't the case. It's their brain that decides to initiate sex and to sire or procreate children. Even many erection disfunctions, may have some component lying with the attitude or the brain? Maybe a mental block, or some disturbing memory of past child abuse or something? But sex is no longer "dirty," if properly procreative in a proper committed marriage relationship, but life-giving and natural, hopefully "overflowing" into more children coming to life.