What I have seen, on the way to work one morning:
Bitch in heat, mounted, 'he' had fallen over backwards and was laying on his back, 'she' was straining forward like a husky pulling a sled...........
.... all while, the rest of the neighborhood 'pack' was chewing him a new azz, 'he' was trying to fight them off, snarling and snapping while being drug across the road, on his back, feet in the air, by his di(k...........
