One weekday morning many years ago I was trying on some tops in the dressing-room of a local store.

I had been vaguely aware on my way in that there was somebody else in one of the booths almost opposite mine, and as I was getting changed I happened to glance through the gap at the side of my curtain and noticed that I could see into this other booth as the curtain wasn't completely closed.

The booths all had full-length mirrors on the back wall and I suddenly realised that I could see the reflection of the woman who was in there. She was facing the mirror, still dressed from the waist down, but only wearing a black bra on top. And I could see that her right breast was out of the bra and was being cradled in her two hands.

For a second I thought I had simply caught a "snapshot" moment of her just easing her breast into the cup of a new bra she was trying on. But as I watched, I realised that she was actually having a "private moment" with her own breast, squeezing it, caressing it, and generally playing with her nipple. Eventually her right hand slid down across her bare tummy, over her thigh and up and under her skirt, whilst she continued to explore her breast with her left hand.

Of course I didn't need to be able to see exactly what her right hand was doing - it was now obvious to me that I'd quite unexpectedly happened upon another woman enjoying her own body in private [the way we girls do!] and, what's more, with the help of the mirror she was apparently enjoying the sight of herself doing so!

Needless to say, I was mesmerised. Even though I was about 20 or 21 at the time, and had had plenty of private practice myself, I had never actually seen another woman masturbate before. Nevertheless I could guess the feelings she must have been feeling and, of course, it was catching. It was a very intimate moment and before long my own right hand was up my skirt and fiddling with my clitty inside my panties, as I tried to stay quiet and hidden behind my curtain.

Even though I was trying not to miss a second of what was happening across the way, I must inevitably have closed my eyes and floated away on my own dreaminess and juiciness. But I was suddenly brought back to attention by a series of muffled gasps, and I could see in the woman's face, and by the way her whole body tensed and quivered, that she was coming.

And as you'd naturally expect, the very thought that here I was, secretly sharing a total stranger's private orgasm, was all it took to push me right over the edge too. It just burst right out of me and I came all over my own fingers.

I must have floated away again with my own sexy thoughts and feelings - and I only came back to reality when the sound of a curtain being jerked along a metal rail made me start back to proper consciousness.

It was the other woman, of course, now fully dressed and carrying her handbag and the clothes she must have been trying on, just stepping out of her cubicle, no doubt about to leave. The noise she'd made drawing the curtain must have startled me into making some kind of noise or movement myself - whatever it was, it made her look in my direction and she did a kind of double-take, and instead of heading off towards the exit, she faltered and then changed direction, walking the few steps across towards my booth.

Of course I just cowered behind my curtain, hardly daring to move or breathe. But of course, she could see me there - it even crossed my mind that maybe she'd known all along that I'd been watching her love herself to orgasm; perhaps it had all been a deliberate show just for me - to this day I'm still not sure, though I have to say she had clearly already started loving herself before I ever first caught sight of her there.

Anyway, whatever the truth of it all, I suddenly realised what it was that she was actually looking at as she crossed over towards me.

In watching her and playing with myself at the same time, I must have copied her and got just one of my own breasts out to play with - because here I now stood, just like she had been, fully dressed below the waist, but only my bra on on top. And there was my naked right tit - the one closest to the gap in the curtain - still hanging out over the top of my crumpled bra-cup, my dark, puckered nipple standing out to attention like a hatpeg!

I stood stock-still as this slim, forty-something brunette came towards me, a knowing smile on her lips and a blush still visible on her cheeks. Because of what I'd just witnessed her doing for herself, I remember wondering whether anybody else meeting her right now would ever guess that her blush was due to the fact that she had just orgasmed! And I remember thinking how privileged I was because I knew this private secret!

But a second later this stranger's face was inches from mine, as she stuck her head through the gap at the curtain and, surprise of surprises - she simply planted the softest little kiss on my cheek. I was gobsmacked! She then stepped back, looked down at my bare tit and whispered, "Thank you!" [I'm still not sure what exactly she was thanking me for!]

For a moment she looked as if she was about to go away. But then she turned back towards me, looked me in the eye again and quietly said, "You're not finished yet, are you, sweetheart?"