That's a tough situation.
I know it's hard but... you had him for about a month, they've had him for almost 2 years. It would break the dog's and the family's heart to take him out of the home. Yes, legally, he's your dog but I'm sure the dog is happy now.
I would just put the papers in their mailbox with a little note to let them know what's going on. I think if you see the dog, you will want him back and that will make it harder on you. |