I know what you mean. I was in the back of the train late at night. There were a few people quite a ways up that were sleeping. I had been sleeping too but woke up with an erection I couldn't ignore.
I hadn't touched my dick (yet) and it was fully erect and pre-cumming. I pulled my pants down and just did it right there. I couldn't hold back either, shooting a big load of sperm into a paper towel I fortunately had in my pocket, or there would have been a big mess. I just wiped up my dick, pulled my pants back up again, and went back to sleep--but my dick left me no choice. It makes most of my decisions as it is, and definitely that one.
I hadn't touched my dick (yet) and it was fully erect and pre-cumming. I pulled my pants down and just did it right there. I couldn't hold back either, shooting a big load of sperm into a paper towel I fortunately had in my pocket, or there would have been a big mess. I just wiped up my dick, pulled my pants back up again, and went back to sleep--but my dick left me no choice. It makes most of my decisions as it is, and definitely that one.