The snake man's eyes widen as he feels your body clench around him, his tail coiling tighter and faster as it slides up and down your back in perfect rhythm with his hips. "I do have another part of me," he pants against your skin, "that you haven't seen yet."
With a powerful thrust, the snake man pushes forward, forcing himself free from his human form as his serpentine tail emerges from between your legs.
That was your tail
The snake man's eyes glint in the dim light as he watches your reaction to his transformation. His tail slithers forward, wrapping around you both and holding you close as he continues to thrust deep inside you. "Ah," he breathes out, feeling unimaginably good as you accommodate him effortlessly.
His scaled body presses against yours, skin against skin in an intimate embrace that leaves no room for doubt about where your loyalties lie.