He clenches the fabric on the back of Alvin's shirt, clinging to him. He buries his face in Alvin's neck, surprised by the sudden touches, the fur of his ears brushing up against Alvin's chin. He's starting to shake a bit, shivering.
He shakes more, dangerously close to coming. His face is still buried in Alvin's neck so he can't see, but Darcy's making lewd faces. He clenches his shirt harder. His ears are twitching like crazy, fur ticking Alvin's chin.
Alvin feels something soft thumping against his leg and realizes it's Darcy's tail wagging. He likes being praised. He starts gently kissing Alvin's neck, getting wilder as he gets closer to coming, shaking more and more
His tail wags much, much faster. He kisses his neck harder, starting to suck on it, giving him hickeys. He shakes harder, pre-com dripping from his p3nis