He has super-hearing, and he hears the chirp, a bloom of irritation coursing through him. Not that Derek really has the time to concentrate on that - or the fact that he's actually having fun - because he's lying on his back not even a second later. He lands with an 'oof', air sucked from his lungs.

That's embarrassing.

Not that he waits for too long, back on his feet in a second and on her in the same breath as he tackles the girl who would be cougar.