She makes a mold of his member and takes him with it.
Seeing her lift her leg up onto a railing and fold her body in half with no apparent effort caused all sorts of ideas to form in Rob's mind, none of them appropriate.
Or were they? Was that not what they were supposed to be doing? Courtney had left Rob with a task. He had plenty of opportunity to at least try to complete it, and yet he had not even made a move to do so. Or at least that's what Karen probably thought anyway. However, he had been making moves: getting her comfortable living with him, being a facilitator in her increased masturbatory activity, and finally by making her feel attractive.
The reason why the thoughts Rob was thinking were not appropriate were not because he was still resisting making good on his promise to Courtney, it was because it was too soon. Karen was not like other girls, he had no way of knowing how she was going to react if he made any sort of direct action towards her, and so he had to be indirect. This was the most obvious he had become, he was putting her in a situation where she had no choice but to think of him in a physical way.
The problem was Rob had not factored in how physically effected he was going to become from being in this situation with Karen. He thought he had greater control over himself, and if Courtney had been around he probably would have because she would have become the center of all his attention, but with her being gone and Karen becoming the implied outlet for these physical desires he could not stop thinking about pulling those damn running crops down Karen's legs and plunging his cock up inside of her.
Then he remembered the tears, and the injuries. How physically and mentally damaged she had come out of what had happened to her. Nearly ten months had passed, and Karen was doing remarkably well through a combination of therapy, her friends, and her own staggering personal strength. However moving too fast would do her no favors and might even cause more damage than good.
This helped Rob focus, to remain patient, to stick to his plan, which if it worked out would be put into play as early as next week. So, Rob stretched and watched Karen stretch. He allowed himself to grow more comfortable in his lust for her, and told himself that it was okay. The arguments Courtney had thrown at him to go through with this rang through his head, and they eased his mind. She was a genius, Courtney was, she knew exactly what to say to Rob even before he needed to hear it.
Karen noticed a subtle change in Rob. He seemed more relaxed, which helped her relax. They sat across from each other on the mat and Karen led Rob through the same stretches she usually did with Courtney, Brianna, or Rachel. She could not help but notice Rob's eyes look down her top as she bent forward in a seated groin and inner thigh stretch. Her feet pressed into his ankles, her legs spread wide, and she bent forward. Karen felt a flutter of pride and also a bit of nervousness at his glance, and perhaps a little something else.
Rob had stretched with Courtney before, and he had thought she was quite flexible. Karen, with her history in dance, was simply ridiculous. She was basically doing side splits and then lowering her torso to the ground. He could see her ass from his erect position, and had to look away before something else took an erect position. Instead he looked at her flushed and sweaty face which looked completely relaxed as she pulled out of the stretch.
Karen gave him a slight smile. "You're turn," she said.
"I don't think I can bend like that," he told her jokingly.
Karen blushed but grinned.