Chloe Loves Mina. Mina does not feel the same way, but because Chloe is a puppy and Mina feels it is her Dog-ly duty to be nice to puppies, Mina puts up with a lot of crap from Chloe. Mina loved Sherman. They would spend endless moments cavorting together. Mina avidly avoids Chloe and when she is forced in close proximity, Mina will do her best to pretend Chloe is not actually there.
Even when Chloe is inside Mina's mouth.
This is how it starts. Chloe tries to get Mina to play by, OBVIOUSLY, biting her in the face.