sowing of the seed". Lucretius recommends "doggy style" (a tergo) for couples trying to conceive, because it mimics the natural procreative sex of animals. Male–female sex The basic obscene verb for a man having sex with a woman is futuo, "I fuck." Although not found in polite literature, futuo was not necessarily insulting or aggressive; it was used transactionally for sex between a prostitute and her client, and in a passionate or loving setting may have been spoken as an arousing intimacy. A fragment from a play by Plautus suggests that acquiring an erotic vocabulary was part of a woman's introduction to sexuality within marriage: a virgin explains that she has not yet learned the words suitable for the wedding night (nupta verba). The easy use of the word by a woman in other settings indicates her independence of social norms, and corresponding lack of status. "Either fuck me or let's fight it out," the formidable Fulvia is quoted as challenging the future Augustus. In graffiti at Pompeii written by both men and women, forms of futuo are used to announce prowess, satisfaction, or availability. Thomas Habinek has claimed that "Ovid invents the category of the heterosexual male", since, he says, it was considered normal for a Roman man to have same-sex relations. Ovid radically rejects the Roman tradition of pederasty, and says he takes more pleasure (voluptas) in making love with a woman as his equal. Sexual pleasure between man and woman, he emphasizes, should be mutual; Ovid instructs his male pupils to make love to a woman slowly, as he advises men not to conclude the sex act without enabling their female partners to achieve orgasm. In one passage, he seems to be recommending simultaneous orgasm: But don't you fail your lady, hoisting bigger sails, and don't let her get ahead of you on the track either; race to the finish together: that's when pleasure is full, when man and woman lie there, equally vanquished. Mulier equitans "Riding" is a common metaphor for the sex act, particularly used of the woman-on-top position. The mulier equitans ("woman riding") does not appear in Greek vase painting but is popular in Roman art. Ovid recommends it for the petite woman, as a tall woman may not wish to seem too towering in relation to the man. Supposedly favored by the mythological couple Hector and Andromache, even though she was of legendary