The carriage is filled with IPod tinnitus and broadsheet origami - a normal commute into London.
He gets on the train and sits down next to me. I cringe inside because I know what is about to happen. He looks normal enough at first but then he reaches into his bag and pulls out his special picture. He always has one. A picture of a young girl who appears to be naked. As usual he is making no attempt to hide the graphic nature of this image despite being on public transport. I look around and can see lots of women and young girls on the train, they are oblivious to what is happening.
I shift uncomfortably away from him, he appears to be aroused. From my vantage point alongside I can see the image of the girl better than I can see this guy's face but, I would guess that he is perhaps 40 years older than the girl in the picture. She looks like a fresh faced teenager, she could be his daughter. She could be his grand-daughter.
The picture is colour and perhaps 10inches long by six wide, in it the naked teenager is staring into the camera and, with her hands behind her back, she is displaying her breasts. Her nipples are erect. The man's lip curls up, as it always does when he is looking at his special pictures. I have seen him do the same thing countless times before, always in public places. Each day he has a picture of a different young girl but the image is always the same, she's always young and Caucasian, always staring into that camera, always showing her breasts. He reaches into his pocket and pulls out a sandwich which he starts to eat slowly, all the time staring at the image on his lap. A crumb falls from his mouth and he delicately brushes it from the teenager's nipple. It seems that he will never tire of this nudity, this power over the young girls before him. He puts his head back and closes his eyes - who knows what the dark author of his imagination is conjuring up inside. Thankfully the image is now covering his crotch.
I look at the picture on his lap, it's always the same - this is no celebration of the female form: the relentless onslaught of this image, day after day, week after week, month after month, the sheer blandness of the image, the replication without style, almost suggests that these girls are all the same.
That all girls are the same.
His eyes open again and they roam from the young face down to her young chest, they flicker up and to the covered breasts of the young woman sitting opposite us, his head nods ever so slightly. The woman opposite looks up, catches him in the act and he quickly looks away. The woman looks at the image on his lap for a few seconds before going back to her phone. She is not shocked, she seems resigned to this situation.
Finally we reach London and we all stand up, I notice that, as usual, he leaves the picture of the topless girl on his train seat and just walks away, no-one says anything. Tomorrow he will have another one.
I pick up his copy of The Sun and fold it closed before putting it in the bin.