A cyber affair is defined as “a romantic or sexual relationship initiated by online contact and maintained primarily through online communication”.  Online sexual activities include behaviours such as cybersexing, where two or more people discuss sexual fantasies on the internet and are usually accompanied by masturbation; Hotchatting, where discussions between two or more people move away from carefree flirting; and emotional actions where people pass on intimate information to another important one.  A new type of online sexual activity is when two people`s avatars engage in sexual activity in virtual reality worlds like The Sims or Second Life. The majority of Americans believe that when a partner practices cybersex, it is an act of infidelity.  Infidelity clauses were at the forefront when Tiger Wood`s rumors sought to reconcile with Elin Nordegren. Nordegren reportedly retaliated by demanding a marriage contract and an infidelity clause with a $350 million fine if Woods deviated again. Gender ratio theory is a theory that explains sexual relationship and dynamism in different parts of the world based on the ratio between the number of men of marriage age and women of marital age. According to this theory, a territory has a high gender ratio when there are a greater number of women of marriage age to men of marriage age, and a territory has a low sex ratio when there are more men of marriage age.  With regard to infidelity, the theory says that when male-female relationships are high, men are rather promiscuitary and have sex outside of a stable relationship, because the demand for men is higher and this type of behavior desired by men is accepted. On the other hand, when male-female relationships are low, promiscuity is less prevalent because women are solicited and, as they want monogamy and commitment to keep men competitive in the pool of partners, they must meet these desires. .