Ever since we moved house Milo became a bit distant, probably mooreso because of the physical size of the house we weren't always seeing him everywhere we went. It was time to get him a buddy and to be fair we've thought about it for a long time and probably should have sooner but our last house was outgrown 2 dogs ago haha. These two are little menaces together tearing up the house at all hours when you're trying to sleep. I swear they are nocturnal! Anyway the grooming thing I believe is a friendly sign of dominance, Kodi was very submissive but as he has gotten older he's pushing back and I think he'll be in charge of Milo soon enough. Luckily Milo got his foot in the door first!