" And that is why I consider promiscuity immoral. Not because sex is evil, but because sex is too good and too important... What sex should involve is a very serious relationship. Whether that relationship should or should not become a marriage is a question which depends on the circumstances and the context of the two persons' lives. I consider marriage a very important institution, but it is important when and if two people have found the person with whom they wish to spend the rest of their lives -- a question of which no man or woman can be automatically certain. When one is certain that one's choice is final, then marriage is, of course, a desirable state. But this does not mean that any relationship based on less than total certainty is improper. I think the question of an affair or a marriage depends on the knowledge and the position of the two persons involved and should be left up to them. Either is moral, provided only that both parties take the relationship seriously and that it is based on values. "

― Ayn Rand