My roommates moaning

I remember being woken up by roommate's orgasmic moaning a couple of times. It was so arousing listening to that. She moved away some time ago, but she still stops by sometime to pick up some remaining stuff she left here. I still think about her moan every now and then. Sometimes I masturbate as I remember it and that is followed by fantasizing about her. I fantasize that I'm in the bathtub where she's taken many baths, and I begin to masturbate to the memory of her moan. Then my x-roommate walks in on me. I quickly cover up with my hands as she apologizes and explains that she had stopped by to pick up some stuff and didn't know I was in the bathroom. I find the courage to tell her that I was actually thinking of her as I touched myself. There's an awkward silence between us, but then she starts undressing and joins me in the bathtub. We begin to kiss and fuck in the water until she orgasms and I hear her moan up close and this time it's by me.