The first time she swirls, there can be no denying the effect. His body twists underneath her, and he cries out quietly, strained and desperate. But he can't go anywhere; her knees have him trapped, focusing all the movement right where he needs it most. All he can do is thrust up into her, hard and fast, and she'll be able to tell the moment he loses control, because his chest contracts, he stops breathing and all coordination disappears.

'Ale...'

He cuts off, jerking into her for the last few strokes until he can't go any higher; the climax hits like a wave - a crash inside, and then the silent pull as she yanks everything out of him, his body rigid and curled under the pressure until he's left stranded with nothing left to give.

He flops back to the bed, hands dropping away because he hasn't the energy to hold on. There's nothing but the warm aftermath washing over him, and the weight of her keeping him grounded.