You continue

Without waiting anymore, you get to it. You get on your knees and move your dad's hands away from his hole. He waits with deep breaths as you slowly insert that humongous cock inside, feeling him tighten all around as he arched his back and released a big moan. That invited you to thrust in deeper and deeper. You also managed to set him off by causing his cock to harden and to release some cum because of the pressure you were putting on his prostrate.