7-9: Chrissy cums as she rides you, and you don't.

You lay on the bed, as Chrissy rolls onto her knees. Chrissy reaches down to grab your dick, stroking it, as she positions herself above it. Slowly, she lowers herself, impaling herself with your dick. Her pussy has already adapted to your size, so you slide in pretty easily. Now she starts to bounce on your dick, crying out in pleasure, as you reach over to cup her big breasts, as they bounce. Chrissy's pace is slower compared to the previous nights that you've had sex with her--albeit in a group play. That slower pace allows her to make the pleasuring last longer, even stop every now and then so that she can gyrate against your hips. When she does that, you rub her clit, making her gasp and moan every time. She repeats this process, letting her tension build up slowly but steadily. While she feels herself about to cum, she realizes that unlike previously, she's going to have to work hard to make you cum. In the meantime, she starts to cum, milking your dick, as her juices oozes onto your dick, and slide down your length.

(Mark +1xp for making her cum. Running total of 18xp.)