The term tribadism is usually used in the context of lesbian sex , and originally encompassed societal beliefs about women's capability of being penetrative sexual partners. It may also involve vaginal penetration by use of the fingers , a dildo or double penetration dildo ,   or refer to a masturbation technique in which a woman rubs her vulva against an inanimate object such as a bolster to achieve orgasm. The term tribade did not begin to refer exclusively to eroticism between women until Late Antiquity. In English texts, tribade is recorded as early as , in Ben Jonson 's Praeludium Poem X in The Forest ,  to as late as the mid-nineteenth century; it was the most common lesbian term in European texts,  through the proliferation of classical literature, anatomies, midwiferies, sexual advice manuals, and pornography. Author Bonnie Zimmerman stated, "More often, however, [European] writers avoided the term, instead euphemistically invoking 'unnatural vice,' 'lewd behavior,' 'crimes against nature,' 'using an instrument,' and 'taking the part of a man.