Beg for it
From Create Your Own Story
You ask her to do it with you, so she'll understand why you would watch and masturbate. She says she will, but only for a minute. You quickly pull her clothes off, without resistance, and put your dick on her labia, pushing it back and forth before slipping it in. She starts to moan while you pound her pussy and play with her tits. As you go faster, she gets more into it, telling how good you feel inside her and how big your cock is. You abruptly cum inside of her, making her moan louder than before, though it doesn't seem like anyone outside of your room heard it. She asks if the two of you can do it again sometime.
