Does this happen to anyone else?

So I've smoke for 6+ years but ive been a week sober and I just took a fat hot rail that got me pretty lit. So much so I felt that I started to precum but it was actually more accurate to say that I just straight up nutted a little bit. Basically while flaccid. Well it started to get a bit hard while I was cumming because the sensation. But my friends said they have never experienced this before. Has anyone else?