http://www.motherjones.com/politics/2016/03/abstinence-education-tennessee-sex-ed-virginity-pledge
One day during the weeklong sex ed class, the female instructor made a show of tearing a long piece of tape from a dispenser. She held it for us to see, taut between her fingers, and pointed out how transparent and clean and sticky it was. Then she handed it to the girl in the first row and told her to attach it to her skin and pull it off. "It won't hurt," she promised. The girl did as she was told, and then the piece of tape was passed around for each of us to follow suit. When it got to me, I gingerly stuck it on my left forearm, smoothing it out on my skin. After I peeled it off, I looked at the particles of dirt and dead cells and hair that now clung to the tape. I wrinkled my nose and passed it along.

Once the tape had collected bits of each of us, the instructor took it back and pinched it between her thumb and index finger. "See how dirty this piece of tape is?" she said. "It's basically trash." This tape, she said, could never bond well enough to stick to anything, especially not another dirty piece of tape. She pressed two fresh pieces together and made a show of her inability to separate them.