I carry in other people's homes, but I rarely visit other people's homes. And I don't live in one of the states that requires you to specifically request permission.
My best friend locally is a fellow Army veteran (albeit he's a generation younger) who knows I am an NRA instructor and that I'm usually carrying. He doesn't mind -- he's trying to find time to take the "Basic Pistol" class from me so he can get his carry license. His only request was that I keep it well concealed if his in-laws happen to be there.
After reading a similar question several years ago, I was talking on the phone with a shooting buddy in another state and I got in my head that maybe I should ask if he minded. So I asked. His response?
"Hell, I'd be upset if you didn't carry. You'd just be one more person I have to protect if you weren't carrying."
After that, I stopped asking.