Everyone occasionally has a spot on their back that itches and it's impossible to reach. That's what spouses are for. Some people have made fortunes by designing back scratchers for the single person to use to reach the elusive itch.
Dogs have a spot just above the tail that they can't reach. Every dog I've ever known has enjoyed having that spot scratched by a friendly human. Even dogs that didn't have a whole lot of interest in being social would stand close by to get that spot scratched.
Tess asks daily to have her back scratched. From there she usually asks for a belly rub. Today the back was the important area. Rob is a good back scratcher.
Fudge saw Tess getting a scratch, so why waste that other hand?
Noah needed a scratch, too. I like how they back up to you to let you know what area needs attention.
Fudge moved away, so Norma Jean moved in for her turn. Rob needs another hand.
Norma Jean doesn't want him to stop. She's still begging for another scratch.