
I'll tell you what worked for me :)
I had the same problem with my dad, who visits most days. He would come in and as soon as Buster would go towards him he would start flapping & paniking. After probably months of me telling him to keep still & calm and DONT TOUCH/TALK TO THE DOG UNLESS HE's SAT DOWN, it didn't sink in :(
One day I had enough, rather than loose my temper with my dad I did an OTT impersination of him, flapping, paniking and generally acting like an child! As soon as I started this, Buster started to get all excited and jump up at
me. My dad was shocked, he said " your dog never acts like that with you, he's alaways as good as gold......" then the penny dropped & my dad felt a bit silly - Buster is as good as gold with me because I am calm, not acting like a plaything - worked a treat :-D
Oh, by the way, my dad is used to dogs, my sister lives with him with her boxer and we had dogs when I was growing up!! It's not just non-doggy people that are hard to 'train'.