Joseph was sexually flexible, enjoying just about any kind of loveplay in most positions. His enjoyment of the act was as much based on his partner's pleasure as his own desires. Helping Rhys discover what he enjoyed was becoming an addiction of its own.
A growl wouldn't have done anything but encourage Joseph to be rougher. Rhys moan spurred Joseph on, he began moving harder and faster on his lover's cock, his own moans swallowed up by the kiss. His fingers tightened in Rhys' hair, as much to keep the Tremere from accidentally biting him as they both drew closer to climax as to add another sensation.