Tribadism is a form of sex when the women becomes stimulated by rubbing her vulva against her partner. This involves no penetration so means there is no chance of pregnancy. It is also used for girl on girl sexual activity.

Tribadism, also known as scissoring, is a sexual act that involves two women rubbing their vulvas together for sexual pleasure. It is a form of non-penetrative sex that can be intimate and pleasurable for those involved.

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This specific position is called scissoring, and is a form of tribadism.

A kind of female-to-female sexual activity involving contact between both partners' external genitalia. It can also be referred to as a form of tribadism.

Source: Wikipedia.