Before she was my MIL
15 years ago is now when I was 18, and mil was 42.
Me and my wife have been together forever, both 33 now but this story is from back when we were 18 and she went to uni in Manchester.
I atvthe time had effectively moved into their home for about a year, not officially as such but would spend almost every night with the gf.
Before she even went away to uni would occasionally hear the mil next door getting fucked by her bf, could tell the gf heard it too but would always just turn the tv on without mentioning it.
Then came her decision to go to uni miles away and stay in halls, coming home weekends. I of course said I would stay back with my parents, but what with her house being so much closer to my work I was told I was welcome to stay whenever I wanted, or even full time.
I would stay the occasional night at my parents, but mostly staying at hers. It wasn't until this point, probably caused by having blue balls from her daughter moving away, that I really started to look at the mil this way. Short, curvy, fairly small tits but a huge arse, and I mean huge.
First time I heard her fucking her bf and I was in the next room without the gf to turn the telly on was so good. Could tell she was trying to be quiet, but he would be fucking her good and hard and she'd let out the odd whimper. For weeks id wank list3ning to them fuck, until the eventually broke up.
That's when one night I decided to take it up a level.... she was out with friends at the pub and I was home in bed early for work the next day. Got to about 11pm and I couldn't sleep so of course decided to wank, when I heard the front door open.
She sounded a bit tipsy fumbling around downstairs, and shouted up apologising for making noise and saying sorry if she woke me.
As she came up she asked through the door if I was awake and wanted anything to eat, she was going to order a kebab. Don't know why but I made the decision so quick to pretend to be asleep and rolled the duvet back exposing my throbbing cock hoping she'd come in to ask again....and she did.
She let out a quick 'oops sorry' and shut the door again, before going back downstairs. So turned on, but gutted she didnt look for longer I continued wanking and came in no time, covering my stomach and chest. Still awake thinking about her, about half hour later heard her coming back upstairs so rolled the duvet back again...and sure enough this time she opened the door without saying a word and looked at me for a good thirty seconds before going to bed herself.
I've got more similar stories of this going further, will post soon