Incidentally, I left a long-term common-law spouse for reasons which included similar behavior.

From the time we brought home our very cute little Rhosdesian Ridgeback puppy, my husband was obsessed with it. Now, these dogs are unique in appearance. They are door stoppers so to speak as they stop most people in their tracks and make quite the conversation piece. They attract attention. Well as mention elsewhere my husband was a narcissist - and this dog was but one of many ways he demonstrated it. Whenever we were in public he insisted that it be he who was the one walking it. He revelled in the attention and it was sickening. He would actually pretend then that I and the rest of the family did not exist - particularly upsetting as the dog was a 'chick magnet'. He would insist upon walking the dog or taking it to the off-leash parks just so as to be the center of attention. It made me irate.

This obsession and behaviour displayed over the dog symbolised all that was wrong with the relationship. I eventually walked away.

So I to an extent get your position and difficulty. I say don't wait to act upon it.