The term tribadism originally encompassed societal beliefs about women's capability of being penetrative sexual partners. A variety of sex positions are practiced, including the missionary position. This may involve vulva-to-vulva contact or rubbing the vulva against the partner's thigh, stomach, buttocks, arm, or other body part (excluding the mouth). Tribadism ( / ˈ t r ɪ b ə d ɪ z əm/ TRIB-ə-diz-əm) or tribbing, commonly known by its scissoring position, is a lesbian sexual practice in which a woman rubs her vulva against her partner's body for sexual stimulation, especially for stimulation of the clitoris. Two women engaged in the missionary position of tribadism and rubbing vulvas, one of the various positions in which a woman rubs her vulva against her partner's body for the purpose of sexual pleasure.