Tribadism ( ) or tribbing, commonly known by its scissoring position, is a sex act in which a woman rubs her vulva against her partner's body for sexual stimulation, especially for ample stimulation of the clitoris. This may involve female-to-female genital contact or a female rubbing her vulva against her partner's thigh, stomach, buttocks, arm, or other body part (excluding the mouth). A variety of sex positions are practiced, including the missionary position.