It was Amadeus who ended up growling and it wasn't one of pleasure but rather one of warning from the beast riding him. The last time he had backed off when the wolf had freaked out from him magically holding Ariel down. This time though he held on, those fangs staying in the back of the Gangrel's neck, forcing it to submit. This could all end very badly but the wolf was other going to have to give and trust him, hand over that dominance for the moment—or end up fighting him for it.
Of course, if he could distract from all of that—well, so be it if it went that way as well. Because even as Ariel struggled to get control over that urge to change, Amadeus was still thrusting into him with his hand working to push his lover into orgasm once more. One way or another Ariel was going to end up losing himself. The Tremere wasn't going to have it any other way.