You can't make yourself stop
From Create Your Own Story
Gwen gently wraps one hand around your heavy member. "Big Bro...." she says quietly, "I want this. I don't know what to do with it, but I want it." Her other hand wraps around it as well. She squeezes and you gasp. She suddenly lets go. "Did I hurt you?" All at once she sounds scared.
"No, it felt so good. It makes me happy. YOU make me happy, Gwen."
Gwen's eyes become as big as saucers. She squeezes you again, and starts pumping like she saw Katelyn do last night. She jacks you harder and harder. Her breathing gets hoarse, and you feel an orgasm welling up in your balls.