make her punish herself

"Nicki slap your ass as hard as you can, and do not stop until I tell you."

"What the fu...." but before Nicki could do anything, she started slapping her ass as hard as she could. "How are you doing this?"

"Suck your thumb while you spank yourself, bitch."

Nicki stuck her thumb in her mouth and started sucking on it. You take out your phone and start filming her.

"Muh ut stup!" she said while sucking her thumb.

"Later," you say. "but no talking or trying to talk." You sit there and watch her. She keeps smacking her ass as hard as she can. You patiently watch her. You know her arm is getting sore from spanking herself and her ass must feel like it's on fire. She is sweating. You just sit there and watch as she grows more exhausted.

"When I say 'now,' you'll be able to stop spanking yourself, but you will keep sucking your thumb. You'll drop to your knees and put your forehead on the floor and hold that position....now!"

Nicki obeyed. She kept sucking her thumb and put her forehead on the floor.

"Put your ass up as high as you can."

Again she obeyed.

"I'll be back," you tell her. You leave the office, making sure you lock the door, so no one tries to come in and put a stop to Nicki's humiliation. You go off to get some supplies to have fun with her.