Even as Jenna felt disgusted by what she was doing, part of her liked it. That must have been the slut part. Even though Jon was in control at the moment, Jenna the slut was still there, still somewhere at the back of her mind. And right now, Jenna the slut was in heaven.
Jenna had to keep her mind in line with Jon and not slip off into the realm of sexual pleasure. Because that's what was happening, as she bobbed her head on Steve's cock. It was pleasurable, and even more so when Steve shot his cum deep into her throat.
When it was over, however, Jon came back in full. Jenna spat out whatever was left of Steve's cum still in her mouth. She felt like vomiting.
"Oh, come on, slut. Don't act like that all of a sudden," Steve said, smiling. "I know you enjoyed it."
Jenna glared at Steve. "I did what you wanted. Now leave Karyn alone."