Tendencies toward non-monogamy and bisexual expression may constitute primate-wide predispositions that have been conserved in humans. This observation is supported by studies of sexual development and behavior in our primate relatives and sexually permissive premodern tribal cultures including hunter-gatherers. Nevertheless, even in sexually permissive societies, there may be considerable sexual possessiveness and jealousy as well as attempts at parental control of children's marital choices. This is associated with punitive revenge against unfaithful spouses and mate poaching rivals and parent/offspring conflict around marital choices. There is no paradise lost despite the greater sexual freedom. Humans may be adaptively designed to suppress each other's sexuality due to sexual jealousy and parental desires to control children's sexuality but also to surreptitiously evade those restrictions, though there is considerable cross-cultural variability in the level of sexual restrictiveness.