Develop your relationship.

You've finally had a taste of sex with Maddie—and, more importantly, she's had a taste of you. From now on, she'll be hopelessly in love with the taste of cum, but there's one problem: she has no reason to prefer your cum above anyone else's. What's stopping her from becoming a slut in order to satisfy her cravings?

Watching that transformation from afar might be interesting, but it's not what you would prefer. You would prefer if every time she got thirsty, she turned to you. So, as you pull your penis away from your disappointed classmate, you add a new rule to govern her future behavior:

Whoever she first performed oral sex on, she will view him as her boyfriend and remain faithful to him until he breaks up with her.

"I guess this makes us a couple," she says, not noticing your typing.

"I guess it does," you say. "Now come on, let's try to get some studying done."

The two of you study for about an hour. At one point, Maddie remarks to you, "I can still taste it in my mouth. It has a really nice aftertaste."

You smile at her, but you don't respond.