on a woman, she was thought of as playing the boy's role. Martial, for instance, is emphatic that anal sex is better with boys than with women; when his wife objects that she provides him with anal sex in an effort to preserve his fidelity, he taunts her with the inferiority of her anus compared with a boy's. The figura veneris in which the woman crouches to lift her buttocks, called "the lioness", may be intended for anal penetration, since boys in Greek art can be portrayed in the same position; with a female partner, it may be difficult to distinguish in art from a tergo (rear entry). Culibonia ("good anal") was a humorous term for a prostitute with this speciality. Avoiding pregnancy may have been one motive for female prostitutes to offer anal intercourse. Os impurum Os impurum, "filthy mouth" or "impure mouth", was a term of abuse especially for those who provided oral sex. "Oral turpitude" was a favorite form of invective for Catullus, Horace, and Martial. An accusation of having an os impurum is an "extreme obscenity", so vile that Cicero reserved it for men of lower standing than himself, only implying that their debasement tainted their more powerful patrons who were his real targets. It was a convention of obscenely comic verse that oral sex caused bad breath that was nearly toxic. "Whores of the alleyways" are contaminated from giving oral sex; Catullus refers to "the foul saliva of a pissed-over whore". The urinary function of the penis makes oral sex particularly repulsive to Catullus, who elsewhere reviles a Celtiberian for brushing his teeth in urine. Martial jokes that a fine perfume turned to garum, fish sauce, when it was sniffed by a man whose breath was putrid from oral sex. In another of Martial's epigrams, a fellator breathes on a hot cake to cool it down and turns it to excrement. The bad breath and rotten teeth that are attributed to performing oral sex represent moral decay and a general corruption of the mouth's positive functions as the organ of a citizen's persuasive speech. Cunnilingus and fellatio Because of the stigma attached to providing physical pleasure, a man who performed oral sex on a woman was subject to mockery. Cunnilingus typically appears in Roman art only as part of a reciprocal act, with the woman fellating her male partner in some variation of the "69"