The onlooker is frozen

As she realizes what's going on, the middle aged woman stops cold in her tracks, and just stares. She doesn't seem visibly disturbed, just shocked, you think. You are trying to get a good read on her face, but can't really concentrate, as all your attention is being stolen away by the unbelievable blowjob you are receiving.

You snap your head back around in pleasure. Looking down, you see the raven haired asian girl, still with one hand stuffed in her pants, using her other hand in concert with her lips, tongue, and throat, to make you harder than steel. It's all you can do to restrain yourself from bucking your hips into her soft warm mouth, but you know well enough to not push your luck when you're getting a blowjob like this. Besides, the delicate touches of her tongue and movement of her head are nothing that you could replicate with mere thrusting.

You feel your head cloud up and your balls contract as an orgasm starts to tear through your body. The asian girl must feel it coming, too, because she immediately pulls her head off your member, and squeezes her hand tight around the base of your cock. Her constricting grip prevents any cum from shooting out of your cock, and any blood from leaving your erection, but you have an intense orgasm none the less, fueled on by the incredible sight of this cute girl squeezing your cock and with a strand of drool between her slightly parted lips and your wet purple cock head. She waits until you stop shaking, and then releases your cock, which has remained hard through this. She then turns over, getting on her hands and knees, and slips her jeans and panties down past her hips, leaving her exposed ass less than a foot from your waving dick.

Just as she does this, you are shocked to see the middle aged woman walk past you on the stairs, and stop on the stair above you. You had forgotten about her, but she must have been watching you the whole time. She bends over, and hikes up her skirt, showing a smooth and generous ass that is starlingly unravished by the sands of time. She reaches back and pulls down the black thong that was covering her ass (although not covering much), and as she does so the strong scent of vaginal fluids wafts up, suggesting that she was masturbating as she watched you receive head.

You now have two asses floating in front of you, two pussies wet and ready for entry, one a tight little asian one and the other a generous but firm white one. You vow to take the late subway trains more often.