Yes they do. They constantly squirt cum at all times when they are erect. They squirt maybe every 1 or 2 seconds for however long until they go soft and the penis goes back in the sheath. It's like a spray bottle honestly when they squirt cum. Their penis doesn't even have to be inside you either, a dog will squirt cum regardless until they go soft and the penis goes back in the sheath. When one has sex with them, the knot is what keeps them locked with you. The knot at the base of the penis swells up as the animal gets more erect as he plants himself deeper and deeper into you with every thrust. Expect to stay in that locked position for 20 minutes to maybe an hour if you are locked really good with him. It's the best feeling in the whole world honestly. It's warm, loving and satisfying all at the same time. Sometimes there is no knotting because the knot has already gotten too big before it could be fully planted in your hole of choice. In this case the dog gets off pretty quickly after he stops thrusting and he licks himself to make his penis go in the sheath. Dogs can go many many rounds, not just one. Hope this helps.