Where were your hands that the lecturer thought they were up? Were you rubbing them above your head?

Ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha that's hilarious. What did the Professor say.

I'd be so embarrassed after that, I'd have just left class early and hid since the teacher was probably going to make you leave anyways.

At least you didn't say you were rubbing yourself

I say shit like that all the time. I was doing inventory with my boss. He is in his 50's so I took the lower shelves. My body was really sore at the end of the day. So I get home and my roommate asks me how I am doing. Before I even think I blurt out "I am sore, my boss had me on my knees all day" *facepalm to the back of my skull*

Oh, no no. I already masturbated at the start of the class. I really was just playing with myself just now.

I come out with things like this all of the time, totally oblivious to what other people are hearing. Said it in front of my Grandparents once, they unfortunately were not oblivious!

I would have said that my hands were cold

If you need to rub your hands together, you need to mutter, "Excellent" Montgomery Burns-style, to avoid confusion with a futile masturbation technique.