My inlaws hated me from the first time we met and 40 years on we still have problems from time to time. After all this time you'd think they'd give up, but no, they still try to cause as much trouble as possible. They never had much of a relationship with any of our children (when my third child was born the MIL just said "not another one" and put the phone down) and we moved away from the area.
So I have always been very careful to accept my daughters' partners - they are their partners not mine - and to make them welcome. I really hope I never find myself doing anything my in laws did!!
To think that London, or anywhere else for that matter, does not belong to any one demographic