Thinking about how during the confession, Crowley was trying so hard to hold back his tears. He looks up, to the side multiple times to prevent any single tear from falling. He's choking on his words, breaking apart because he knows it's too late by this point. But he's pushing through it, just to tell Aziraphale he wants to spend the rest of his life with him, because maybe it'll change his mind.
You can see the moment he can't hold it back anymore. The moment he realizes they're not on their own side because Aziraphale chose heaven, and has to get out of there, has to put up his defenses.
Getting a good boy so close to their release you can already see their eyes rolling back, can feel their clit pulse, their cock throb, the little sounds leaving their mouth getting impossibly needy. They're so sweet, even telling you that they're going to cum.
All that to just - stop completely. To see the confusion, the desperation in their eyes turn into tears as you repeat the act again and again and again until the boy under you is nothing but a dumb, whiny mess. Babbling and begging, sobbing and drooling, only a wrong look at their pretty parts could send them over the edge.
Having a smart boy not even remembering his own name because his only thought is the wish to cum. This is power.