It was hot. The kind of fuggy heat that left everyone damp and lethargic. On the train it was even worse. Whatever air conditioning system it was that was supposed to be cooling the evening commuters wasn't working and the carriage stank of sweat. Standing room only, of course. We were packed, but people were careful to maintain a distance. Polite sardines. I was holding onto a roof bar, swaying with the movements of the train, planning my evening. Then, suddenly, a whiff of something in my nostrils, rising over the baseline stink of my fellow commuters...
Above the general hum of humans locked in a small, hot space was an increasing odour: high notes of stale urine, the deep musk of old body odour, the earthy stink of worse, human waste. And below it all, the unmistakable smell of sex, unwashed orgasm. I'd just started to look around, trying to pinpoint the offender, when I felt a body press into my back. The soft swell of breasts around my shoulders, a hard pelvis pressing into my ass and thighs. I tensed, waiting for an awkward apology and the body to step away. It didn't. And I realised the smell was coming from them, the person pressing into me. I inhaled again and my cock twitched, involuntary. I should have gagged, should have stepped away. I didn't. Despite myself I was suddenly hot with arousal. Almost giddy.
A pause, only a few seconds, probably, but it felt like minutes, the body at my back gently rocking into me with the sway of the train. And then, suddenly, wet lips at my ear. An overpowering wave of unwashed breath. Alcohol, cigarettes and, again, the musk of stale sex. "You like it, don't you?" their fetid breath caressing me as they spoke, voice harsh, gravelly. Used. I was still frozen. Still half expecting, half hoping for, a muttered apology, 'Sorry, thought you were someone else'. I didn't step away. Didn't say a word. Couldn't. I felt pinned by the putrid, irresistible stench rising around me. My cock twitched again. I did like it...
"You do, you filthy fucker..." Now I felt their crotch grinding into my thigh. A slick wetness soaking through my trousers from them. The heat of them. A hand was at my thigh, fingers probing, searching for the waistband. A 'normal' person would have pulled away, recoiled. Instead, I leant backwards into them.
"Ah. I chose well." The hot, wet, voice in my ear again. The hand moves, having found a path, down, under my waistband. Sticky fingers wrap themselves around my shaft, now rock hard. I groan, finally, the first sound I've made.
"Hard already? Doesn't my... scent put you off?"
I can still step away, I think, lose myself in the crowd. "Wait, What... Where..." I whisper, trying but failing to articulate some of what I was feeling.