@fluffy @VD15 Dogs have a different anatomy from humans, a dogs penis is shaped like a torpedo, and depending on the breed it's around the same size as a human, with the same variations humans have. Some dogs have microdicks, some dogs have giant dicks. Even small dogs can have a big dick, or a big dog has a below average dick. It's all individual. Anyway at the base of the cock is an area that swells up in the general shape of a ball, and it's called a knot, it's purpose is to swell up inside the hole the dog is fucking (generally the vagina but dogs don't care much) to act like a natural buttplug, and keep the dog inside the hole, it takes around 20 minutes for the dogs erection to go down enough for its knot to pop out and for the rest of the cock to come out with a *schorpt* sound, and then a river of cum generally pours out because canines cum a LOT (not as much as pigs or horses though).