Calling a prostitute to have sex, only to discover on the way that she's the neighbor's wife. (Hinamori Miko, MOND-112)

I wanted to treat myself after a hard day, so I invited a married woman to my house for some sex. But halfway through, I realized I'd seen her somewhere before. Then I was shocked to discover she was my neighbor's wife. So I used that as leverage and had sex with her without a condom until I was completely blown away!