From 2009... Circumcision and semen displacement: Circumcised men were more likely to have cheated on their female partners and to think that their partners had cheated on them

From 2009... Circumcision and semen displacement. Sara M. Ressing, Rebecca L. Burch. Northeastern Evolutionary Psychology Society. 3rd Annual Conference, 2009. https://neepsociety.com/wp-content/uploads/2009/10/NEEPS2009PROGRAM.pdf

Abstract: This study intended to examine differences in semen displacement behaviors between circumcised and uncircumcised males in a college population. Circumcised men were more likely to have cheated on their female partners and to think that their partners had cheated on them. However, reactions to these suspicions, such as mateguarding, physical violence or sexual violence did not differ. Both types of men reacted to suspected infidelity with increased thrusting speed, depth and vigor. While uncircumcised men routinely had intercourse in the missionary position, circumcised men were more likely to engage in lateral entry and female superior positions and in anal sex. Although both men and women report similar thrusting depth, speed and vigor, circumcised men and their partners reported a significant decrease in thrusting behaviors after orgasm. Uncircumcised men may continue thrusting for a longer period after orgasm. While this would presumably result in more displacement, after orgasm it would serve as self semen displacement.