Sometimes the bull likes to tease my wife like that. First he gets her immoblized so he can control the act at his will only. Then he starts by fucking her slowly and increasing the speed as she gets excited but he never thrusts more than half of his cock. This creates a tension in her womb, craving to feel the tip of his cock against it. Then when she is incredibly wet and nearly cumming, he puts all of his cock at once and keeps pushing, without moving anymore. This immediately brings her orgasm and he says that he can feel her womb opening against the tip of his cock, ike trying to swallow it, as her body convulses in a passing out orgasm.
(Source: daddys-little-kittens, via cumfuckmywife)