After the door closed behind my girlfriend and our dirty old landlord I sat frozen for a few minutes not really sure what to do. The spell was soon broken though by the sound of bedsprings. The rickety old bed made a real racket at the best of times, but by the sounds of it Derek had just sat down quite heavily on it.
I moved quickly and as quietly as I could over to the bedroom door to see what else I could hear, the first thing I heard was Derek laughing.
"He's listening at the door now, I can see his shadow." he chuckled, "I bet he's having a wank."
Sally joined in laughing but the bed creaked again and her laughing was muffled and turned once more to moans, I could only guess but it sounded like they were kissing again and that he had his hand in her knickers.
My stomach was in turmoil and my cock was raging hard, so I decided that I might as well play along and unzipped my jeans and pulled them and my boxers down to my ankles. Grabbing my cock I leaned against the door my ear pressed up against the wood listening in to the sordid sex session my eighteen year old girlfriend was having with our fat, balding forty odd year old landlord.
"That's it love," he grunted on the other side of the bedroom door, "lick up the length and then suck it into your mouth...oh fuck that's it, good girl."
I could hear slurping and sucking noises and moans from my girlfriend's throat as she sucked Derek's cock on our bed. He laughed again and she broke off giggling, "Sorry love my belly gets in the way a bit doesn't it?"
The bed springs creaked more, and I guessed he'd lain down, "There you go, get this in your mouth," he told her.
"Mmmm you dirty old bastard," Sally giggled before resuming the slurping and sucking sounds I'd heard earlier. I desperately tried to keep a slow pace to my wanking as I didn't want to cum too soon, but I was having a really hard time of it as I listened in.
There was more creaking from our bed as Derek told Sally to move around a bit, "Hang on a sec let's get these off," I heard him say.
A few moments later she gasped, "Oh fuck yeah lick my cunt." Then giggled, "Ooh that's dirty you can't lick me there! Oi! I didn't say stop!"
They both broke into laughter again, then the sucking and slurping sounds resumed only broken by the creaking of the bed and moans of delight from Derek and my girlfriend. I didn't know how much longer I could last without cumming and it took a superhuman effort to stop myself when I heard Derek tell Sally to stop sucking.