The guy’s facebook has photos of the fox as a kit dated june 16th, he lives in the forest so they usually met the fox on their evening walks, and the pair playing starts in september. According to him, it’s afraid of all other dogs and humans.
Ah, thanks for the extra info!
Still, interesting that it wasn’t fearful of them. Cubs start developing their fear and flight response around 5-6 weeks, so for a 3 month old to befriend a dog is still very unusual. I wonder what it was about Tinni that didn’t scare off the cub?