grooming each other, chances are they are both purring their contentment. Purring can be misleading though, cats will purr when they are in pain as well as when they are contented. When MacKenzie was in the worst of her contractions today, her purrs filled the closet.
Everytime I've tried to see if my babies were purring for each other I seemed to distract them. Then of course they wanted my attention.
And yes, I knew that they sometimes purr when they are in pain or perhaps scared. It's their way of trying to confort themselves or calm down. I wonder if there is a noticeable difference in the way they purr when they are content vs when they purr in pain?