this is an account of something that happened in the early 80`s when my wife, mary was in her mid thirties. she came home from work one night looking very flushed in the face and a bit upset. i asked her if something had happened at work to upset her. `not at work` she replied, `on the tube`. after half an hour of cross examination i had the full story; it transpired that for the last couple of nights, while on the train coming home, some pervy old bugger had been feeling her bottom. it started with just the occasional light touch, but had now reached the stage where he was actively squeezing her cheeks with both hands. after calming mary down with a stiff gin and sending her upstairs to run a bath, i began to mull over the situation and to my surprise i found i was greatley turned on by the thought of my wife being groped by a complete stranger.a plan began to form in my mind. let me describe mary as she was then; about 5`4", small tits, narrow waist, great legs topped by a very large round arse. she was also very submissive by nature and always open to mild forms of sexual experimentation. obviously the old groper was an arse man and he was unable to resist copping a feel of mary`s magnificent bottom. this then was the plan; the next night, mary would finish work 10 minutes early and meet me at the tube station. she would enter the ladies toilet and change into some clothes that i would bring with me. the said clothes consisting of tight fitting, very thin white silk dress, nylons & suspender belt, heels but no panties. when i told mary what i wanted her to wear on the tube, and that i wanted to watch while the old geezer fondled her arse, she went ballistic, and it was only after much pursuasion and sweet talk that she very reluctantly agreed. so, there we are, mary clicking down the platform in her fuck me shoes, me several paces behind, watching her bare bottom bounce and quiver under her tight dress. as we joined the crowd on the platform,i glanced around me, trying to spot the old perv that mary had described. i did`nt have to wait long, for as soon as mary stood still, a private frazer ( dads army ) look-a- like slid out from behind a stanchion and stood close behind her. soon the train pulled up and everybody shuffled forward to get on the already full carriage. mary found a space near the far door and `frazer` took up his station close behind her, i managed to locate myself slightly behind him and to the side. as the train pulled away i looked at mary and she glanced me and i saw a very worried look on her face. chummy had clearly not wasted any time and had started feeling mary`s arse. at this juncture, all i could see of him was his face, and judging by the look of amazed delight that was on it he had discovered that all that seperated his trembling fingers from mary`s bare bottom was a very thin layer of silk. after half a dozen stops, the crowd had thinned out slightly and i was now able to see that he was now rubbing her suspender straps through her dress while simultaneously thrusting his groin into her bottom. mary`s face was a picture...very red and angry, but also a hint of something else...she was turned on, i was sure of it. all too soon it was time to leave the train and as mary stepped towards the open doors i looked down at gropers crotch and saw a large damp patch on his trousers. on the way home in the car mary was all a twitter telling me how he had stuck his very large penis between the cheeks of her bum and thrust away for all he was worth. `disgusting`. as soon as we got home i made mary strip off her dress and when i felt between her legs she was absolutely soaking...dirty girl. only one thing for it; a good hard spanking followed by a good hard fuck. then i broke the news to her that next time, instead of the tight dress, she would be wearing the short pleated skirt. but that`s another story.