Gaylord is a beautiful dog! I'm sure once they all have a change to get adjusted things will go smoothly. My parent's oldest dog was 12 before a new dog came into the house (they now have 4 total) The cahnges in her over the last year have been amazing...she plays more, she tolerates humans more, she'll go for car rides now, and she is learning to play with other dogs! That's not to say everything has gone smoothly...there have been some small fights here and there, but overall, it works
I agree with everyone else, if Killi is acting more playful, this could be a rally good thing!

Hope your Thanksgiving goes well. Hugs to all three dogs!