When my dog was a puppy I took her to my friends house. She was fine with everyone in the house (including friends brother, in his 60s) but hated her husband. Growled, barked, hid behind me, wouldn’t go to him, hid behind a chair growling at him ... all quite unusual.
Fast forward almost two years, friend and husband come to visit (just in the back garden). Dog again hated this particular man. She’s bigger now obviously and mature, she growled, continuously barked at him, heckles raised ... he put his hand out for her to sniff and she started air snapping at his hand. She just wasn’t going to warm to him at all so we had to separate her. How bloody weird!!
Friend then told me their own dog doesn’t like him either?! AIBU to really wonder why?