What's the difference between pet play and being a little?

Both swap adult responsibility for something simpler, but for different things. A little takes a younger human headspace: comfort objects, bedtimes, being looked after. A pet takes an animal one: moving differently, communicating without words, being played with and trained.

Pet play is often the more physical and the more public of the two, with a large gear culture and its own munches in most big cities. Little space tends to be more private and more about the relationship than the room.

People do both. They are not the same headspace, and most people who do both will tell you they feel nothing alike.