The change in positioning didn't jostle them and didn't interrupt Caius's feeding. Although, to be fair, he was far too engrossed in the taste of Eloise's blood—which he had essentially been depriving himself of thus far by not revealing his true nature to her—that he could hardly be bothered by a positioning change.
Now that she no longer had to brace herself against the bed of vines beneath, Eloise raised both her hands and slipped her fingers into the dark locks of Caius's hair, encouraging him to stay as he was and continue to feed on her.
Caius, should have taken over the task of bracing against the bed of vines due to the change in positions but the vibrations of Eloise's conjured musical notes took care of that and supported him.
At some point though, Caius had to stop feeding. He could tell he was getting so lost in the moment and could end up taking more from Eloise than he should so he pulled away from her neck.
