That is just adorable! Too cute! Awe, our cats and dogs always loved eachother like that too, but not quite as much grooming eachother. I think when they grow up together they maybe think they are related or siblings or something.
real cute It reminds me of my golden ret. and my dark gray and white cat. They both groom each other and they often sleep together. The cat actually does NOT like other cats. He chases my other cats. However he will sleep with the golden and likes to play with my bunny. He even tries to get into the bunny cage when the bunny is running around the kitchen