Grusha loves you, he just has a hard time telling you that. You'd be blessed with the muttered "I love you" considering how rare it is. Sometimes Grusha comes back from a battle before he has the time to relax himself, still heated from the battle, and he'll offer you loving excited kisses and words of affection.

Basically you know he loves you. Even now, when you're quietly watching a snowboarding race, his hand is clinging to yours, occasionally squeezing when something excited him.