I'd discovered that my new girlfriend Ellen wasn't the moody type. She didn't get easily upset. So I was a little surprised one day by a small but sudden change in her mood. We were at the mall, and she had asked me to come with her into one of those chic women's boutiques where she was going to leave a dress to be altered that she'd bought there earlier. She left me waiting by the cash register while she went back to the dressing room to drop the dress off. When she left she was in her usual pleasant, cheerful mood, but then when she came back she seemed suddenly distracted and nervous. I wondered why, but she didn't say.

She said only that the tailor was there, and that he would alter the dress but first needed to measure her. She told me she would be right back and then walked back to the dressing room.

It's sort of funny, but as I watched her walk away I was thinking about her body. I was thinking that it didn't really match, in my mind, with her personality. She was what you call a "nice" girl, sweet-tempered and modest, not given to flashy or wanton behaviour. She didn't wear low-cut dresses, wild earrings or lots of mascara. She wasn't a virgin when we met, and we'd had sexual intercourse pretty regularly, so she wasn't a prude, if you see what I mean. But she didn't wear a tiny bikini at the beach or display her body much, and I'd never heard her refer to anything sexual in public before.

But under her plain, pretty, Ann Taylor clothes Ellen had what can only be described as rather a lush body. Full, heavy breasts, which always surprised me a little with their weight when I cupped them. Big rosy nipples, a full red mouth. Generous hips, flaring out from an hourglass waist. And a perfectly proportioned ass with a deep, smoothly sculptured crack dividing her round cheeks. Anyway I wondered about Ellen's change of mood, and wondered if the tailor had given her a hard time or something about the dress. Vaguely thinking about giving her some kind of moral support if she got into an argument with him, I drifted back towards the back of the shop. As I got there I saw that there was a doorway leading to a set of little alcoves with the usual white-painted half doors for trying on new clothes. Ellen must have come through here. I walked in, a little nervously and kind of on tip-toe, hoping I didn't come across a half-dressed woman and get yelled at.

I didn't hear Ellen's voice. I saw that the corridor continued to the left, and then turned right. I guessed that the tailor's shop was further back. Was Ellen back here? I walked around the corner.

There *was* a shop, and there were tables and scraps of clothing all over them. The place was a mess. I still didn't hear anybody, though. I started picking my way through the clutter. Then I thought I heard a sound like somebody breathing heavily, and I heard a low murmur, like somebody talking softly. It was a man's voice, pitched low, asking something, urging something.

Quite suddenly and perfectly clearly I heard Ellen's voice. She said ``All right, but quickly,'' and she said it in a normal tone, not whispering or anything. Her voice came from my right, around past a huge table piled high with dresses, over which I couldn't see. I peeped past the table and froze. For a moment I didn't quite understand what I saw.

What I saw was a man, young, with dark hair and an elegant white shirt on. That must be the tailor, I thought. He had no pants on. His legs were spread slightly. Kneeling gracefully in front of him in her pretty, modest gray striped dress was Ellen, her heavy black hair moving gently as she withdrew the man's stiff, wet penis from her open mouth.

Ellen stood up suddenly. As she turned toward me I ducked behind the table, my heart beating fast. Between some dresses I could still see her, but she couldn't see me. She brought her hand up to her mouth and wiped off a trace of saliva from her chin. She had put on a little lipstick earlier today, but now it was all smeared.

Ellen turned away from me, hiked her dress up and pulled her panties down to her ankles. She reached down and took them off. Then she laid them carefully next to her on the long wooden counter. She turned around and lifted her dress up, over her naked ass, and bent over the counter.

Reaching back with her pretty right hand, on which our engagement ring sparkled, she gently spread her bottom cheeks apart. I could see the slender, delicate folds of her vagina, surrounded by her trimmed, dark pubic hair. When I looked back at the tailor he was moving his hand up and down on his penis, smearing some oily stuff all over it. I noticed he had a really big dick, and it was thick and stiff as he ran his fingertips lightly over the glans. Standing up behind Ellen the tailor put one hand on her naked back. From where I was I could see him perfectly. He guided his penis to Ellen's bottom, and positioned the head between the cheeks of her ass, pressing directly on the brown circle of her anus. And then slowly, but without any hesitation at all, this man pushed his stiff penis all the way up into my girlfriend's asshole.

Ellen didn't really make any sound. The tailor grunted when he entered her, and sighed deeply when his penis was finally up all the way inside her, with his hairy hips resting firmly against Ellen's smooth white buttocks. He began stroking his dick slowly in and out, back and forth into Ellen's bottom. He put his hands on her hips to steady himself, and began to accelerate, thrusting more and more urgently into her asshole. I couldn't help but imagine his dick swelling as he penetrated her again and again, getting harder and longer as he became more excited, so that each thrust of his cock probed deeper and deeper into Ellen's full rectum.

Ellen began to moan gently, in time to his motion, a little "oh! oh!" coming from her at the top of each stroke, just when the man's penis filled her most completely. Suddenly the tailor gripped Ellen's hips hard and he began thrusting urgently, forcefully. He took bigger, longer strokes, and a few times I could see the smooth head of his penis emerge completely from Ellen's anus before poking back into her. He began growling and snorting loudly, and I could see he was about to cum. I began to shake a little, with what emotion I don't know, as I imagined his thick white cum spurting up inside Ellen's ass, and thought of how she would feel his cock throb and swell in the tight ring of her buttocks.

``Ahhhh!'' he suddenly cried out. He stopped thrusting. Shifting his hands from Ellen's hips to her thighs, he pulled her towards him hard, straining urgently to push his dick just as far up inside my girlfriend's ass as he could. For a moment he stood thus, holding her trapped and penetrated body tightly. Then he groaned and his muscles grew slack, and he released her. As he staggered back I saw his softened, slick penis slide rapidly out of Ellen's anus and pop out. A tiny thread of white semen dripped from the tip and landed on Ellen's white flesh, resting between the cheeks of her beautiful smooth ass. He never touched her breasts at all.

Well it was hard to know exactly what to do, and my mind was all in a haze anyway. My thoughts were racing, jumbling together, memories of Ellen's chaste kiss after our first date, and the shy way she had later let me caress her nipples under her sweater, mixing together with what I had just seen, Ellen spreading her generous buttocks apart so that a strange man could more easily push his penis up into her anus. I stepped back behind the table where they couldn't see me. I heard voices and movement, and I realized that if I stayed where I was I would surely be discovered. I needed more time to think, so I walked rapidly and quietly out of that back room, past the dressing alcoves, and back into the main store. The noisy shopping environment of the store as I emerged seemed surreal to me, the women stepping sharply by in the aisles, high heels clicking on the polished floor as they swung their shopping bags, or pursing their lips and frowning as they fingered skeptically blouses and scarves on display stands. The very sexlessness of the whole mall shopping bustle contrasted so strongly with where I had just been, watching a woman being fucked up the ass, that I just felt dizzy.

What was I going to say to Ellen? Only a few minutes had passed since she first went back, and she would be coming out very soon. In fact, she came out even as I was thinking this. She looked normal, walking briskly towards me and smiling gently in her usual way. Her dress swung naturally, and her red lipstick was no longer smeared, but I thought I could see that her black hair was a little bit mussed. And of course I thought of that tiny pearl of semen I had seen lying in the crack between her buttocks. Did she know it was there? Had she wiped it away before she put her panties back on?

Ellen and I left the store. She told me the tailor had agreed to alter the dress and that she would be coming back to pick it up in three days' time. We walked out into the main mall and toward the music store that had been our destination when we first arrived. We passed a family restaraunt with a big glass window in front. There were a couple of teenaged boys eating inside and they watched Ellen and I walk by. They looked a little jealously at Ellen, and at first I felt a little proud, as I always do, to think of this good-looking woman by my side -- I could see Ellen's reflection in the restaraunt window, and she looked real sharp -- pretty dark hair, sweet smile, nicely shaped legs and large, firm breasts standing up high under her dress. But then I thought: this woman standing next to me, her hand in mine, has her ass full of another man's cum right now.

The thought made me queasy, and I wanted to sit down. I asked Ellen if she wanted to go in and have lunch. She said yes, and in we went. We sat down, and a waitress brought us menus. I was looking at mine when Ellen suddently said she wondered if they had a restroom here. I said they probably did, and then she said she was going to go ``freshen up a bit.''

Now years ago when I was younger I had a girlfriend who wanted to try anal sex, so we did once or twice. I found out that when you fuck a girl in the ass it's a little like an enema, and afterwards she'll often need to go poop, and then your cum dribbles out of her rectum.

I didn't remember this fact right away, sitting in the restaraunt studying the pictures of chicken sandwiches and hamburgers on the menu. But then suddenly it came back to me all at once, and I realized exactly why Ellen needed to go to the bathroom and what she was doing there now.