Honestly, I would just leave Leo at home when you visit them. His dad is right that it is his house, so he shouldn't have to put his cat away BUT since his son is allergic to him, I would think that he would put the cat up. My MIL is allergic to cats and we clean really good before she comes over and the cats go upstairs in a bedroom for awhile. It doesn't kill 'em! lol
On the note of what the great aunt said, I wouldn't worry about it too much. YOU love your baby and that is all that matters. He is adorable, but some people just aren't dog people. It was very rude of her to say that outloud though. There are a few dogs (not any on YT of course
) I've seen that aren't very cute to me and I either just don't say anything or I pretend. I don't want to hurt anyone's feelings and despite what the dog looks like, it still a living being and deserves to be loved.