penis in his partner. Allowing himself to be penetrated threatened his liberty as a free citizen as well as his sexual integrity. It was expected and socially acceptable for a freeborn Roman man to want sex with both female and male partners, as long as he took the dominating role. Acceptable objects of desire were women of any social or legal status, male prostitutes, or male slaves, but sexual behaviors outside marriage were to be confined to slaves and prostitutes, or less often a concubine or "kept woman." Lack of self-control, including in managing one's sex life, indicated that a man was incapable of governing others; the enjoyment of "low sensual pleasure" threatened to erode the elite male's identity as a cultured person. It was a point of pride for Gaius Gracchus to claim that during his term as a provincial governor he kept no slave-boys chosen for their good looks, no female prostitutes visited his house, and he never accosted other men's slave-boys. In the Imperial era, anxieties about the loss of political liberty and the subordination of the citizen to the emperor were expressed by a perceived increase in passive homosexual behavior among free men, accompanied by a documentable increase in the execution and corporal punishment of citizens. The dissolution of Republican ideals of physical integrity in relation to libertas contributes to and is reflected by the sexual license and decadence associated with the Empire. Male nudity The poet Ennius (ca. 239–169 BC) declared that "exposing naked bodies among citizens is the beginning of public disgrace (flagitium)," a sentiment echoed by Cicero that again links the self-containment of the body with citizenship. Roman attitudes toward nudity differed from those of the Greeks, whose ideal of masculine excellence was expressed by the nude male body in art and in such real-life venues as athletic contests. The toga, by contrast, distinguished the body of the sexually privileged adult Roman male. Even when stripping down for exercises, Roman men kept their genitals and buttocks covered, an Italic custom shared also with the Etruscans, whose art mostly shows them wearing a loincloth, a skirt-like garment, or the earliest form of "shorts" for athletics. Romans who competed in the Olympic Games presumably followed the Greek custom of nudity, but athletic nudity at Rome has been dated variously, possibly as early as the introduction of Greek-style games in the 2nd century BC but perhaps