I covered this in my last larry proof book, but there's just so many good and kind of unexplainable GIFs of larry mirroring each other that I really wanted to add some more parts.
In case you don't know of this phenomenon, here's what mirroring is.
Louis and harry have just been caught in sync so many times that its really kind of an unexplainable proof, imo. I mean, sure, you could mirror your best friend if you've known each other long enough, but it's really more reasonable to think that it happens with a s/o or spouse.