Now that I think about it, does the girl have a name? and who does she have sex with, her boyfriend? husband?
if you're an otaku loser like me, you might be able to identify this character as Yuki from "Alya Sometimes Hides Her Feelings in Russian". I used her card because her features are generic enough to pass for a normal girl, but being an actual character means that the card is beautifully made
the person she has sex with is you. interpret the relationship however you'd like