"You heard me." Susie said. "Just do for me what you did for your friend here and I won't make a scene about you being bare-ass naked."
"You... you promise you won't tell the boss?" Mackenzie asked, hardly believing that she was contemplating giving in to this ridiculous demand.
"The boss won't hear a word about one of her employees showing up naked, you have my word." Susie said, holding a hand up in a show of honesty.
Biting her lip, Mackenzie took a deep breath and closed her eyes. As her left hand reached up to her chest and began gently squeezing her generous chest, her left hand drifted down between her legs and slowly began stroking at her lower lips. Trying to shut out her very public surroundings, Mackenzie tried to imagine that she was sitting at her computer rather than Rachel's car, the browser window open to one of those sites her friends didn't know she visited. It wasn't long before moisture started to build up between Mackenzie's legs, and her fingers easily slipped into her soft entrance, slowly pumping back and forth.
Rachel and Susie could hardly believe Mackenzie had been talked into doing this, but they certainly weren't going to complain. Rachel took the opportunity to pull out her phone again, making sure to get shots of Mackenzie's body from multiple angles. Rachel noticed that Susie had a similar idea, her own phone in her hands and focused on Mackenzie, though it looked as if Susie was going with a video recording rather than mere photos.
"Wow. You know, I like your style." Rachel said, giving Susie a little nod of respect. "You don't care that this is your friend you're taping?"
"Friend? Mackenzie's not my friend." Susie said, flashing Rachel a devious grin. "We're coworkers, sure, and we get along well enough. But this is some prime blackmail material. If I ever want someone to cover a shift or do one of the crappier jobs, I've guaranteed Mackenzie will work for me. And maybe I want this for some more personal reasons."
"Ooooh, nice!" Rachel said, commenting both on Susie's rationale and Mackenzie's lewd performance. By this point, Mackenzie was lost in pleasure, her hips thrusting out to meet her fingers as her other hand upgraded from soft groping to pinching and twisting her erect nipples. A minute or two later and Mackenzie was at her peak, pulling her hand away from her chest so she could bite on her finger to keep from screaming as she climaxed. Juices leaked from between her legs, coating her other hand and soaking into the fabric of the car seat. Slowly, Mackenzie's eyes opened and her face reddened as she returned to reality, realizing just what she had done and where she had done it.
"Okay Susie. I did what you wanted. You won't tell the boss about any of this, right?" Mackenzie pleaded, hoping her coworker was satisfied.
"Yeah, the boss won't find out. For now. Now, I have a question for your friend." Susie said, turning her focus to Rachel. "My shift is over in an hour or so. Would you mind waiting for me? I've got a ton of ideas for stuff Mackenzie could do.
Rachel was intrigued at this. She certainly wouldn't mind having another cruel mind helping her humiliate Mackenzie. But on the other hand, sitting around waiting for her shift to end would be boring.
"If you can't wait that long, well, I could go on break right now. I'd be fine with, oh, let's say ten minutes in the back seat with Mackenzie here." Susie said, offering a compromise. Suddenly, Rachel was looking at a win-win. Now Rachel had to figure out which sounded more fun, wait an hour for a partner in humiliating Mackenzie, or subject Mackenzie to Susie's whims for ten minutes?