Luke is 4 years old and he does the oddest thing. He absolutely fears (dislikes?) one specific person we know. First, he's an odd duck in that he's a bit too robust in his greetings when anyone comes over. He's an in-your-face greeter. Loud barks, then he quickly runs to find a toy to bring the guests to play keep away. Same routine every single time, no matter who comes over. He's the same with men and women. Then, after the initial bark, he'll eventually come to the person for pets or gives them a lick on the face. Except for one friend. His reaction is so extreme. She comes over and he barks nonstop at her. If I show him the spray bottle, he'll back off. But then he'll stay as far away from her as possible, and yesterday he did something he's never done, he went upstairs by himself and stayed there for an hour or so. We were all downstairs. If she walks to him, talking sweetly, he barks and backs off and will run into the back yard. He won't take treats from her. He'll even do that thing where he will peek back around the corner at her. There's absolutely nothing wrong with her. She's a total animal lover and has had huge dogs and currently has cats. Our other dogs love her. We thought we had a breakthrough the other evening. I'd had enough, so another friend and I sat with her on the living room floor and sort of patted her and tried to entice Luke to come to us. He balked and barked and ran, but after about 15 minutes or so, he cautiously came over, several times and even liked her face once. He also seemed to sort of butt her a little with his snout, but I'm not sure of that. He doesn't growl or seem to threaten to bite. (He's not vicious, seriously, but at 120 pounds, he's intimidating.) When she came to take photos of the three dogs a couple of months ago, each time she came closer, he would sort of bark and puff out his cheeks and blow like a horse. Anyway, after our "breakthrough" the other day, I thought it would help, but when she came by yesterday, it was the same thing all over again and that's when he went upstairs. I suppose we can pet her and play that game each time she comes over. Anyone have a dog who behaves this way toward one person? Thanks.