Nathan didn't push it on her. It had to be her own decision, and though he knew he could easily guilt her into it, that wasn't how he wanted to go about this right now. And besides, she should know he wouldn't let any harm come to her.
He pressed the edge of the vial to her lips after releasing a breath he didn't know he'd been holding. He tipped it back with her help and he watched as her throat moved, swallowing it. He felt a surge of lust as she did that thing with her tongue, and so he made a low growling sound.
"Mm," he said in approval, pressing her tightly against him. He thumbed off the lid of the other vial and took his own dose, licking his lips to make sure he got the last of the taste. It filled his veins with even more heat, a familiar but welcome set of sensations.