My aunt is 44 and about 5ft 2in, she has medium tits and the ass of an 18 year old. One day I was helping her paint her new business. She was wearing a sweat shirt and sweat pants (with holes in the ass). It started to get hot in the room we were working on and she took off her sweat shirt and she was wearing a light orange tank top that was a size to small.
I was taking a break and she was pouring more paint and when she bent over I saw her nice ass staring me in the face and a tiny little black g-string with a hoop holding it together. I could clearly see the tight dark skin of her beautiful ass, I got an instant hard on.
For the rest of the day I could see her thong and parts of her ass cheeks, I was in heaven. Then the best thing happened she was on the ladder and asked me to make sure it didn't tip, my face was inches from her ass hole. So I moved my face as close as I could without touching her. I could smell her beautiful ass and caught a hint of her pussy I almost came right there.
After she no longer needed me holding the ladder I said I needed to use the bathroom (which was attached to the room we were working on) I went in there and stroked my cock and moaned loudly as I came. To this day I'm sure she heard me. The rest of the day I spent painting and staring at her ass. She even gave me a nice view of her tits down her shirt.