NOT KNOWN FACTUAL STATEMENTS ABOUT MATURE

Interest in anal intercourse has also come from research in human immunodeficiency virus (HIV) transmission. Quite a few experiments have quantified the improved risk of heterosexual transmission from one act of anal intercourse as compared with one particular act of vaginal intercourse (Boily et al., 2009; Leynaert, Downs, & de Vincenzi, 1998; Pow