When Isabella enters the scene, the slave is lazy on a gymnastic ball on his back... ready for a ride!
She steps over him, decends her round ass on his chest like it would be a saddle, and with some bounceers she moves back on his throat and then on his face.
Occsionally she lifts her ass for letting him a sip of air, but soon she drops back on his face or throat, the ride can go on.