Amphitrite felt her throat constrict - not enough to kill her, not even enough to damage her, but enough to make it just a little harder to breathe. She trusted her husband. He always knew exactly how far she could be pushed, how far she would let herself be pushed.
(It was more accurate to say - although she didn't think of it that way - that Amphitrite had come to enjoy and find acceptable the exact levels that Poseidon wanted to go to anyway. A perspective shift had been what it had taken for Amphitrite to become who she was with him.)
On Poseidon's lap it was an easy enough thing to slide one leg across the other side to that she was straddling him, his hands still gripping her tight as one of her own reached down between them to touch him, to draw out the reaction she desperately wanted.