Buddy is definately letting you know that Reese is coming into season. He's investigating her rear end to see if she's ready for mating, the neck licking is an affectionate type of kissing. The urine tasting, especially with the lip quivering (always reminds me of Hannibal Lecter in the film
) is also very typical behaviour.
You need to be really careful now to prevent them mating, best is to keep them apart. If you haven't noticed any bleeding, then she's probably keeping herself very clean, so you've no chance of telling when the discharge clears, her vulva softens & she's ready to accept a dog, which can be anything from about 9 days into her season. As you don't know when she actually started, I;d keep them apart now if I was you.
As for the thin coat, that could well be diet related. I always prefer to feed my little dogs, my Cairns as well as Yorkies, 2 meals a day. One in the morning & the other in the evening. I think perhaps she isn't getting quite enough. A very good food for growing a good coat is Royal Canin Yorkshire Terrier, if you can get it. I have to order it specially here where I live. It keeps their teeth nice & clean too.
Hope this helps a bit
