This happened when I was about 22 and my, long ago ex, girlfriend was about 19. My girlfriend used to share a house with two friends and she was very open. She would often walk around the house in various states of undress and her two (female) housemates were just used to it. She was also very experimental and open sexually, so it was a fun relationship to be in.
Due to her openness, her best friend new an awful lot about her sexual escapades and would often tease her. One birthday her friend bought my girlfriend a double ended dildo, seemingly as a joke.
My girlfriend was slim, had dark hair, with small tits and a nice round ass. She also sported quite a big bush, which I loved. She loved anal sex and we would do it often.
One day, probably in the middle of the day, we were having a really good fuck. As we were fucking, she rolled onto her side and took the double ended dildo out of her drawer. She told me that she wanted dp with the dildo in her pussy and me in her ass. She laid on her side, pushed her ass out and told me to fuck her ass. I rubbed some lube on my cock and her asshole and slowly pushed my cock inside her.
I slowly fucked her ass for a short while before she told me to stay deep inside her. She lifted her leg and told me to hold it while she started to push the double ended dildo inside her pussy. I felt the dildo rub my cock while it was in her ass, making her ass feel even tighter. As she held the dildo inside her she told me to fuck her. I started to slowly fuck her as we heard a knock at the door.
My girlfriend grabbed the duvet and threw it over us as the door opened. It was her best friend. She looked at us under the duvet and laughed, well aware that we had been fucking. She called us dirty bastards and looking at me asked if we were going to uni as she could give us a lift. I was stunned and still rock hard in my girlfriends ass. My girlfriend laughed and pulling back the duvet to display herself naked with a purple double ended dildo buried in her pussy said “Give me a few minutes”. As her friend just ogled and laughed my girlfriend started to fuck herself with the dildo.
Her friend turned to leave and as she was pulling the door shut, my girlfriend loudly said “I’m close, fuck my ass and cum inside me” Not needing any further invitation I did just that.
Source: reddit.com/r/gonewildstories/comments/nehjxd/we_mf_got_interrupted_whilst_having_sex