You couldn't take it anymore and began to rub your clothed boner.

It felt so good to you then you moaned almost too loud, shivering. You began to rub at medium pace, shaking with ecstacy for masturbating in public is such a rush. You was in the back of the train, isolated from everyone else so you had a chance to cum. Your face was tinted pink and you removed your jacket to see your boner. You realized your wetted your pants a bit due to precum and it made you more turned-on. It felt so amazing, until you noticed that a really hot guy was looking at you. You couldn't stop though. You're so close to cumming and you groaned, shivering. "O-Oh no, I-I'm gonna...in front of him..."