Desire in anal intercourse has also come from analysis in human immunodeficiency virus (HIV) transmission. Many studies have quantified the elevated hazard of heterosexual transmission from 1 act of anal intercourse when compared to one act of vaginal intercourse (Boily et al., 2009; Leynaert, Downs, & de Vincenzi, 1998; Powers, Poole, Pettifor, &