After being called away by a brainless thug to run an errand, he ended up sleeping with my girlfriend. (Asuki HND-381)

I was always bullied during my school years, but everything became wonderful after I got a super hot girlfriend in college. However, one day, the most arrogant and brainless thug in the area found out that I had a girlfriend and actually demanded that I bring her to meet him. He also asked me to run errands for him, and then he took the opportunity to take my girlfriend to have sex with everyone...