This involves a large tarp.

South African artist Jeremy Brown sells kits designed so couples can make paintings while "being intimate with each other."

The kits contain a non-allergenic canvas and non-toxic, washable paint, plus a large tarp, two pairs of disposable slippers, and a body scrubber. So to be clear: you're covering yourselves in paint then having sex on a canvas. Kits range in price from $60 to $110, and obviously make an ideal Valentine's Day gift. Plus, 20% of all proceeds this season will be donated to the World Food Program, so you're actually killing THREE birds with one stone (the sex bird, the art bird, and the charity bird).

Source: loveisartkit.com