Facesitting and buttdrops with the riding mistress

I know this slave loves my riding outfit and he'll endure whatever i demand - and i want to make him suffer under my butt today. i sit down on his face firmly and smother him under my ass, but the facesitting is not the only thing he'll have to endure. again and again i drop my butt with my full weight on his body and make him suffer under my ass in this way as well - and then i sit back down on his face! the mix of smothering and physical pain makes it really hard for the slave to recover in between and his suffering gets worse and worse over time!