Sexual partners are people who engage in sexual activity together. The sexual partners can be of any number, sex, gender, or sexual orientation. The sexual partners may be in a committed relationship, either on an exclusive basis or not, or engage in the sexual activity on a casual basis. They may be on intimate terms (in which case they are often referred to as "lovers") or anonymous, as in the case of sex with a stranger, a one-night stand, or a prostitute. A person can be another person's sexual partner even if the sexual activity is illegal, socially taboo, or otherwise in breach of a trust or commitment. A person may have more than one sexual partner at any one time, either as polyamory, polygamy or in contravention of convention.