Nikutai Kankei

From JuneManga:

“When I met the cool stud Narusawa at college I said half-jokingly, "Screw me next!" Before the day was out, he had. Our relationship was supposed to be just physical, but now I realize I'm falling in love with Narusawa. Looking back on it, it's a one-way love I brought upon myself. I'm much too embarrassed to tell the purely physical Narusawa "I love you" now!”