You manage to hold it in.

With all your might, you restrain yourself from thrusting further, and you hold back your orgasm. Your cock trembles violently, and Sophie's hand hovers precariously close.

She doesn't take your cock, but she doesn't need to. The sensation is overwhelming, and you desperately try to calm yourself. You strain against your arousal, but you're so close. You try to focus on something else. After a moment, you think to look at at the faces of the other girls in the class...the ones who aren't half-naked and inches away from you.

There's Kuniko, Sophie's friend, there's Samantha, obviously enjoying the show, there's Grace, taking notes as usual.

As you look around, your dick spasms a couple times, burning off its extra energy, and you're finally able to relax. You'll make it to the next phase of class, whatever that might be.

In fact, what do you want to happen next? You've already let this class restart for your own fun and enjoyment...and it seems that if you cum it'll just reset again. Is there anything you want to try?