Triggers of women’s jealousy and mate guarding, as a consequence, should focus heavily on signals of these kinds of losses, such as a man becom-ing emotionally involved with another woman. Emo-tional involvement is a signal of the long-term com-mitment of resources to the partner with whom one is involved [15]. Sexual and emotional infi delity in a partner, of course, are correlated in nature [16]. People tend to become emotionally involved with those with whom they have sex. And people often become sexually involved with those they are emotionally close to.

For men, a single failure at mate guarding could result in genetic cuckoldry, as happens when man’s wife becomes fertilized by a rival man’s sperm. In addition to the direct loss of opportunity for reproduction, the husband risks investing years or decades of his own effort in a rival’s child in the mis-taken believe that the child is his own. To compound these reproductive losses, his wife’s maternal efforts now benefi t his rival’s child rather than his own. Fur-thermore, if the lapse becomes public, the cuckolded man risks damage to his social reputation, which could bring about a decrement in mate value, a loss of sta-tus, and an increased future vulnerability to other mate poachers. Finally, the cuckolded man suffers opportu-nity costs – matings that he could have pursued as alter-natives had he not engaged in this particular mateship. Large are the potential reproductive costs of a single lapse of mate guarding.

One common strategy is the concealment of mates from intrasexual competitors [4]. Concealment is usually accomplished through one of three means –removing the mate from the vicinity of rivals, produc-ing signals that mask the attractant signals of the mate, and muting the conspicuousness of courting and copu-lation to evade detection by rivals.

All these confl icts occur because the deploy-ment of a successful reproductive strategy by one individual can interfere at multiple points with the reproductive strategy pursued by the other – a phenomenon called “strategic interference” [2].