Her boss just enjoys her lack of inhibitions

After the conference call was over, Casey was bent over her boss' desk and he fucked her ass. She would never get tired of how good it felt to have her ass fucked by such a big cock...

"I want you to start calling me Master when we're alone, Casey. Sir will suffice when others are with us, but Master when it's just the two of us, understood?" he asked.

"Yes, Master! Please keep fucking my ass, Master!" Casey moaned out.

"Such a good slut..." he praised her, and slapped her ass, before he put a pill bottle on the desk next to her, "These are meant to increase your stamina, so you can fuck for hours on end. I'm sure you'll need them. Take one every morning before you come to work. You can use them at home if you wish too, just tell your husband that you bought them if he asks. Take one now."

Casey grabbed the pill bottle and happily swallowed one pill, before she moaned out as she felt herself somehow growing more aroused. Then he pulled out of her ass and sat down in his chair, but Casey _ached _for him, so she quickly moved to sit in his lap, letting his cock fill her ass again, before starting to bounce eagerly on his cock.

"I don't have any more meetings for the rest of the day, Casey. Plenty of time for you to service my cock..." he said.

And they certainly did fuck the day away. At the end of the day, she was giving him a titjob, and the last of many loads of cum he'd given her splattered all over her tits.

"Don't clean it off, Casey," he said with a grin, "And make sure you leave enough buttons undone to show my cum covering your chest. You can only clean it off when you get home."

"Gladly, Master..." Casey mumbled, doing up just enough buttons on her blouse to show off the tops of her tits and the cum that covered them, "See you tomorrow, Master."

People stared as she walked through the office, but she paid them no mind. It felt so good to be marked by cum like that, and she absent-mindedly used her fingers to scoop some into her mouth to swallow on the drive home.