This is different from opening a vein and letting him drink. The feel of it is...

Then it was calculated. It wasn't this intimate slipping under his skin, this body trapping his as the feeling of being fed on rakes across his senses. His breath hitches by impulse, not out of true need, and there's a slight arch of his hips that says maybe he's more affected by it than outward appearance might suggest.

Still waters. Inside he's moaning, clawing, begging for more, even if all that escapes in another soft sound and the tightening of his fingers.