Boo will hike his leg against your leg when he wants you to play with him. The first time he did this, my DH was freaking out because he thought Boo was going to pee on him.
But it quickly became apparent that it is Boo's cue to play. Boo will also bump you with his bum as an invitation to play. The first few times he did it to Gracie Ruth he bump her off her feet. He learned he had to be gentler with his bumps when he was playing with her.
