Yvette's gym-ball-sitting-game

The slave is on a gymnastic-ball ready for Yvette to play with.

She mounts his chest like a horse and begins to bounce.

She tries how high she can bounce, but it gets unstable, she don't want to lose the balance, so she moves higher on his throat and face, bouncing less, but still sitting with all her weight, she enjoys the feeling of a good slave-crush under her ass.