girls' elbows, gratification from
Tell a fit but dim girl that only girls can touch their elbows together behind their backs. If she tests this, she will push her chest out, thereby providing the watching boys with their daily ration of cheapies.

Don't bother asking flat-chested girls, no matter how fit or dim they are. Wait until 6th form when they'll probably have caught up.
written by ru* bor, approved by Matt