Eren/Levi

When your born your given an animal. You learn the ways of the animal and grow up looking for your mate. When you kiss them for the very first time, whatever animal you were given is what animal you become crossed with. (Explained in the 1st chapter). Eren is a heart throbber at his school. He's rich because of his father and he plays with any girl he wants. He kisses girls waiting for the day his wolf ears and wolf tail will pop out. But it never happens until he meets silver eyes. What happens when Eren has a hard time communicating with his mate?