Most men are excited by the idea of their women being with other men. Yes, most. They may or may not actually like it. But many an otherwise sensible gentleman finds himself aroused upon seeing his hotwife, girlfriend or significant other flirt with a stranger, or perhaps a friend. He may be jealous, hurt, angry, even enraged. Still, he can’t help but want to make love to "his" woman as soon as they get home, his erection stronger than usual, and his ejaculation more powerful. It's as if he is pumped up to win some sort of sexual competition with the other male for the prize of this valuable female, his wife.

A more adventurous gentleman might even encourage his lady to have sex with the other man, "cheat" on him with lovers, dress in "slutty" clothing when they go out in the presence of other men, or at least talk about the fantasy of being with another man, perhaps while pleasuring her with a large dildo, which *represents* the other man.

Traditionally, this kind of husband is called a cuckold, an old English word that carries connotations of unwilling sexual submission and shame. Many cuckolds, willing or not, are sexual submissives in their relationships, helpless slaves to their women's desire for other men, or their own fetish for being cuckolded by their "slutty," often cheating wives, sometimes masturbating as they watch their hotwives get it on with "alpha" males, even sexually servicing their wives' well-endowed partners or being the subject of intense humiliation .

But most gentlemen who enjoy watching or imagining their female primemates* having sex with other men in threesomes, at swing parties, in porn or with dildos, don't feel humiliated at all. They do feel extremely excited, and experience harder erections and stronger ejaculations than usual. Some so-called cuckolds effectively dominate the scene, choosing lovers for their hotwives, sometimes advising the lover as to how to turn on the wife, much like a film director selects a leading man for his leading lady, and then coaches him on how to play the scene.

What do all these very different types of cuckolds - the Submissive, the Dominant, the Sissy, the Swinger, the Director (just to name a few) - have in common? They are all extremely aroused by seeing, hearing or imagining their women having sex with other men.

So, what is going on here? There are many explanations, but one of the more compelling reasons for this type of male arousal lies in human evolutionary biology.

Up until the last couple of decades, biologists thought that there was only one kind of sperm in semen with a single goal: to swim to the egg and inseminate it. It was assumed, quite wrongly, that the ejaculatory release of sperm was like the proverbial gunshot before the big race that has all the little tadpoles swimming directly to the egg. In the 1990s, evolutionary biologists Robin Baker and Mark Bellis found that these “egg-inseminators” make up only about one per cent of a man’s sperm count. So what about the rest of the tadpoles? It seems that most sperm behave less like a bunch of individual marathon racers than a football team, with some players playing offense and others on defense. They discovered that many sperm don’t swim to the egg at all, but clearly hunt and kill sperm from another man that might also be in the vagina into which they and their brothers have spurted. These killer sperm actually contain *weaponry* that destroy the *enemy* in a Sperm War. Or, using football terms, they are the offense, tackles and fullbacks in the Super Bowl of Sex going on inside the woman. Other sperm on a man’s *team* play defense, blocking and protecting their inseminator-quarterback brothers from other men’s warrior sperm.

Why Sperm Wars? How did this genetic football game come about? Scientists speculate that, like our cousins, the bonobos and common chimps, our human ancestors were not monogamous, and often several males would mate with one fertile female within a few days of one another. These different men’s sperm would then intermingle within the one woman, duking it out for the evolutionary reward of fertilizing her egg.

Sperm Warfare explains men’s passion for football and other war games, as well as male excitement over female nonmonogamy

Whenever a gentleman gets ready to have sex with a lady, he unconsciously considers the odds of her being with another man. If he feels the odds are that she is totally faithful to him, he might be very happy about that, but his erection won’t be at its strongest, nor will his sperm count be at its highest. Unconsciously, his testicles *know* they don’t have to fight an adversary, so they need not generate the full army (or football team) of several hundred million sperm. Therefore, he *conserves* semen. After all, he only needs to send in a few sperm to reach an egg where he has no rivals.

But if he feels he could be a cuckold, if he suspects he has a cheating wife, if he sees his lady having sex, or if he just feels that she might--whether he likes the idea or not--his testicles will spring into action and produce as many hundred million warrior sperm, blockers and inseminators as they can. The result is that the man has a much stronger erection, more copious ejaculate and a more intensely pleasurable orgasm than he routinely does.

A happy cuckold gives his hot wife a pedicure as she makes a date with another man

Apparently, the human male is wired to be aroused by sexual competition. This is one reason why so many men are drawn to so-called "slutty" women, despite the fact that so many societies, around the world and throughout history, have consistently and vigorously denigrated sluts.

This also explains why so many men love pornography. When a man views porn, he tends to watch a woman he desires having sex with someone else, usually another man, or maybe even with several men, as in the popular gangbang genre of porn. Some male porn lovers enjoy watching women masturbating or lesbian porn, but the vast majority of men choose to watch heterosexual porn. Essentially, they are watching a slutty woman with another man or men. This tends to trigger a stiff Sperms Wars-powered erection.

The Sperm Wars theory also explains why so many men, even if they adore their wives, get sexually bored with them after a few years. If a gentleman feels there is no possibility that he could be "cuckolded," and that his wife could cheat on him, that she could be with another man, his sperm count will stay *comfortably* low. After all, no sense sending out the whole football team of sperm when just a few runners will do the trick.

This is not to say that couples can't stay monogamous and enjoy hot sex for many decades, but such couples usually utilize the power of fantasy, either together or individually. But a long marriage that never even entertains the possibility of cuckoldry, i.e., another man having sex with the wife, is almost inevitably doomed to low sperm counts and comfortable boredom in the bedroom.

A hint of rivalry excites the male, reminding him that his woman is worth fighting for, bringing his sperm count up and making his erection rock hard. Of course, the danger is that jealousy, even "retroactive jealousy" over past lovers or "fantasy jealousy" over future lovers or paranoid jealousy over imaginary lovers, might overwhelm a man to the point that the Sperm Wars going on within his balls only adds fuel to his rage and fear. The Sperms Wars cocktail is a potent one, and can be quite dangerous in high doses or when experienced at the wrong time or place. Thus, a lady must respect her gentleman’s boundaries; with some men, playing the Sperm Wars game is playing with fire.

But remember: the woman doesn’t actually have to have sex with the other man to create the scintillating Sperm Wars effect. It is only necessary that her primemate think she might, even if he just imagines it, and even if everyone knows it's *just* a fantasy. Indeed, for most couples, the power of Sperm Wars and the experience of being "cuckolded" are best and most safely explored in the realm of the imagination.

Now, if only we could keep the wars to the sperm, and stop the wars between people…

~Susan M Block, Ph.D.

*A primemate is a "primary mate." A couple may have more than one sex partner, but they are each other's primemate.