Some guys just get off on taking risks. You can tell by the amount of pre-cum this dude is leaking out the end of his dick that he’s uber turned on by jerking his dick in public, on a moving train no less. He looks around to make sure no-one’s too close, before pulling open his jeans and pulling out his rock hard cock.
He pulls the camera close so we can see the huge drop of pre-cum leaking out his uncut dick, before putting his finger into it and tasting the sweet nectar. He then finishes up by shooting a thick load of cum onto his fingers and cock… Yummy!