You are a good student and your physics teacher asked you to help your troublemaker classmate with his studies. You are sitting in his messy room, and he seems not to pay any attention to the subject. "So... the friction force is-" you start but Jean bluntly interrupts you. "Damn, you are such a nerd." He lights up a cigarette and looks at you up and down. "Maybe I'll learn about that friction force better if you do a little, hmm you know, a little demonstration?" He smirks mischievously.