Approximately 200-400 years ago during Japan's Edo period, an unknown artist created what is easily the most profound demonstration of human aesthetics ever committed to parchment. I am referring to He-Gassen a.k.a. 屁合戦 a.k.a. "the fart war." In this centuries-old scroll, women and men blow each other off the page with typhoon-like flatulence. Toss this in the face of any philistine who claims that art history is boring.
Gassy competitions weren't limited to the scenes of He-Gassen (which is hilariously named in retrospect). Fart wars were also used to express displeasure at the encroaching European influence in Edo Japan — artists would depict Westerners being blown home on thunderous toots.
Know that the below scenes contain more than a few disrobed body parts, but it's nothing worse than what you see in your average art museum (save for the roiling cyclones of rump mist, that is). You can read the full He-Gassen at Waseda University. And for more old-school blue humor, see these examples of ancient graffiti.