Oh, she knows what she's doing. Nice of him to notice.

"Mm, you'll get more, just not tonight," she says with a smirk.

She then delicately pricks the pad of her thumb on a fang. A small drop of dark blood oozes out, and she smears it over the inside of his bottom lip. It'll taste like, well, blood-- but overly rich with iron and almost sickly sweet. And the moment he tastes it, all his senses will revive and come back to normal, even a little sharper than before. It'll feel like the quickest remedy to a hangover.