Cum inside your sister's womb
From Create Your Own Story
With a loud moan, your cock pulses and cum begins to flow. Your sperm races up your shaft and exits into her, load after load leaving you and entering her. With so much pressure in her cervix and your loads still pumping, your sperm break through her inner sanctum and start to flood into her fertile womb, flowing hard and fast inside her belly. You can even see the pulses against her tummy as each spurt of your seed left your cockhead and entered her insides. She stirs a bit and moans as the last spurt of sperm fills her. Satisfied, you exit her twat, confident that you have just impregnated your sister with your virile seed.
You: