Arkady quivers at the promises Ereuvir makes, as well as his own form of talking dirty. The idea of letting Ereuvir fuck him while Ashley watches, or them both watching Ashley, as well as the very idea that there's going to be more between the three of them, makes Arkady let out a breathless, "Yes. Gods yes."

His thrusts get harder, faster, shifting so he's thrusting against Ashley's sweet spot. "I still know your body so well, my love."

The view of Ashley and Ereuvir having a moment makes Arkady give a particularly sharp thrust. It's a combination of arousal and a reminder that a part of Ashley will always belong to his brother. Arkady brushes a bit of Ashley's hair aside and leans in to bite his neck.