SDMU-032+ "When we have sex, my boyfriend always wants to penetrate my asshole, but I can't even stick a finger in it, so it ends up being awkward." Ling (college student, 20 years old), Yuka (college student, 22 years old), and Mika (college student, 19 years old) wanted to please their boyfriends with anal sex, so we developed their anuses.