He really isn't thinking of stopping. That wouldn't be beneficial to either party. And it is good, it's really fucking good -- but John thinks that he could live with a little less good just to be a little more frequent.
And then he wonders why he's thinking so fucking much when he could just as easily be fucking. So he does that instead, fingers digging bruises into Q's leg and hips sharp in jut and thrust and fuck and also yes. "God," he says, and bites Q's lip just so he can make himself stop babbling.