The slave lies lazy on the sofa, like he's awaiting to be sat on!
And this is, what Rosie does!
Immediatly she sits on him like he's nothing and uses her ass for burriing his face.
She sits in different direction, mainly with all her weight on his face.
Sometimes she lifts her long legs in the air, for ensuring that really all her weight crushes the "happy" face under her ass, and she's enjoying the struggeling under her, because this makes her bounce and intenses the ass-crush-effect to his face.
She loves to ride'm out!