A sexual act in which a male attempts to place his testicles into the
asshole of his partner (preferably female but male-male action is possible also). Ideally, the
asshole being to tight the testicles will repeatedly pop back out like a when you try to put a dog in a bath tub. The
asshole should be well lubed and loose enough to allow partial testicle penetration. Not an ideal position for virgin or gaping assholes.