So one time, when I was in middle-school (I was 12, I think), we had a medical exam. What I didn't know is that they were gonna inspect our penises. There were 2 nurses, one was just fresh from med-school and the other was 50-something. The young nurse pulled my pants down and I immediately got a boner. When she touched it, I came all over her hands, shirt and cleavage. The other nurse just giggled and said "it happens".
So even after all these years, I still get a tingling sensation in my pantsu when I remember that day.
Feels good, man.