This happened a couple years ago at the suite I used to rent.
When I was 32 I rented a basement suite in a house, the landlord and lady lived upstairs and they were both in their late 50's. The laundry was shared and for them to use it they had to come into my suite, which they did when I was at work.
Well this one day my jeep was in the shop so she must have thought I wasn't home. I was sitting on my couch watching a good porn on DVD, totally naked and stroking my eight inch uncut cock, I had been going for a good 30 minutes so I was rock hard. Next thing I know the door opens, she sees me jacking off, smiles turns around says sorry and leaves. Of course I continue to masturbate. A minute later a knock at the door, so I say come in...it is her again.
Now she's not the best looking lady, but oh well. I guess she figured I would have been finished, as she starts to turn around to leave again, so I say 'Don't worry it's ok, what would you like' while still stroking. She replied, 'I was just going to come and apologise for barging in because I thought you weren't here.' I said 'not to worry and if you need your laundry to go ahead and get it' She said 'okay thank you' the whole time staring at my cock.
As she walked back to the door, she said that I had the biggest cock she had seen, and that it was double the size of her husbands. By now I was really turned on so I told her if she wanted to she could stay and watch me finish, well she sat right down on the couch beside me. Her eyes glued to my crotch, she started rubbing herself through her pants, then asked if she could touch it. I of course said yes, she grabbed it and was amazed at the size and hardness of it...I reached over and slid my hand down inside the front of her pants and panties and started rubbing her pussy, she didn't object...she had a very wet and hairy pussy, and I slid a finger up inside and rubbed her clit. After about five minutes she told me she wanted to watch me finish myself off. I took over and stroked my cock, and told her I was going to cum and shot seven big ropes onto the coffee table in front of me. She said that was incredible and said she hoped we could do it again sometime, and maybe next time she would get naked too...too bad I don't live there anymore...!!