Poor Everett is at that awkward size ... too big to ride Prince, and too small to straddle him! Oliver found it quite amusing when Everett fell off.
Shadow is far too mature to join in the fun, but is quite content to stand back and watch.
We have the same issue in our house. Our dog is always going between the boys legs when he's playing. He tries to do that to me and almost knocks me down. I am not tall enough! LOL!