Eric could feel her wants, he knew what she desired him to do. He only kept from doing it as a playful tease, but the taste of blood had indeed been the breaking point. He had denied himself so much recently. He didn't want to deny himself further.
When his lips found the delicate curve where he neck and shoulder connected, he bit. A real bite, this time. Immediately the hot blood was in his mouth.
With every exchange, they grew closer, him and Baba Yaga. It was a thought that didn't bring him any pause, that she should feel what he did and vice versa. He actually enjoyed sharing his life with her, letting her in as he did.
When he finally unlatched himself from her, Eric moved to kiss her lips, so that she might taste her own blood.