 He knows that something isn't right with Midnight. You can see it in how he treats her. Normally, he'll stomp up to you and give "best friend big friend hug!" I've seen (and experienced) the hugs he gives. Bone-cracking would be a compliment. With Midnight, I don't think I've seen him ever hug her. Maybe a pat on the back or gently wrapping an arm around her, but never a yak hug.. 