Protein Shakes.

At first Beth did not understand what William meant, but when he started undoing his pants, she suddently understood what he meant by protein shakes.

Memories of the previous day, where she had been **** to eat his cum off her face came back to her and she remembered the awfull taste.

However she knew better than to go against William and she got on her knees and crawled under the desk.

"You can start." William said as soon as he had his cock out of his pants. Beth looked at the already stiff cock in front of her and opened her mouth.

Four days ago, Beth had been a virgin who had thought that fellatio was disgusting and humiliating. She was sure that she would never give a blowjob because it was unnatural and degrading. Now she was naked under a desk sucking on a hard cock, while the boy in front of her was editing a video of her getting ****.

William enjoyed the feeling of Beths inexperienced mouth around his cock, she had a lot to learn and he was the right person to teach her, he thought to himself.

As he sat there enjoying the blowjob and editing the video a thought hit him and he couldn't help but smile.

"Listen up, slut..... from now on, when I tap your right shoulder you will speed up. If I tap your left shoulder, you will slow down and finally, if I tap the top of your head, you will go deeper."

Then to test if Beth understood the new rules, William tapped her right shoulder and Beth picked up the speed of her blowjob.

William leaned back in his chair and enjoyed the slurpiing sounds coming from the girl between his legs. He could not believe his luck, for years he had been dreaming about training his own **** and finally he got to live out this dream.

Then he tapped Beth on her head and she started taking more of his cock into her mouth, he smiled an evil smile as he noticed that the slurping sounds changed to gagging sounds as his cock hit the back of her mouth.

The new sound reminded him that it would soon be time to break in her throat, so that she could deeptroat him in the future. But it would have to wait, because right now he was very close to cumming.

He tapped Beth one more time on her right shoulder and the speed was picked up even more.

"OK, slut..... you are about to get your reward..... You better not spill a single drop of my precious cum. I want you to keep it in your mouth and show it to me before you swallow it."

Then William let go and shot his hot cum into Beths mouth.

Beth gagged as she felt the cum filling her mouth, but she kept her mouth closed around the big cock in her mouth.

Finally after what felt like ages to Beth the cock in her mouth stopped spraying cum and she carefully removed her mouth from the cock. She was careful not to spill any semen.

"Open up your mouth.... and look me in the eyes."

As she looked up at William, she could see that he was holding his phone filming it. She did not know how much of her blowjob he had been filming.

She opened her mouth and William took his time documenting the big wad of cum in her mouth.

Then to Beths big horror, he spat right into her open mouth, while he was filming it.

"Now mix it up before you swallow it."

Beth could feel her stomach turning as she did what William had ordered.

Finally after mixing the cum and the spit in her mouth, she was allowed to swallow the disgusting mixture.

"Congratulation, you have just gotten your first of many protein shakes straight from the source." William said as he padded Beth on the top of her head.