Looking for old story

Story by booobp

Hi,

An old story came to mind, it was something along the lines of two friends or sisters don't recall exactly. 

But one was a futa, and they were able to fuck each other quietly cause the futa would retract her penis back and forth into herself while her partner was sitting on her. And they would do it while their roommate was around but the roommate or friend that found out and wanted to join them .

I think they were in college and roommates, not sure. 

If anyone recalls this, I think there were only 2-3 chapters. 

thanks