She can keep them

John shook his head and pushed her panties back toward her.

"I want you to see you wearing them for the rest of the day. Keep your tits out, too, and don't clean up any of that jizz. I like seeing you marked."

His step-mother blinked for a moment, briefly stunned by his sudden boldness before shaking her head and laughing quietly.

"You think your father would like seeing it?" she asked, cocking an eyebrow as she leaned back against his dresser and started threading one leg at a time through the sticky panties. "I can't imagine the look on his face when he comes home from work and catches his wife dressed like a porn star with his son's dried cum all over her. But that's the whole idea, isn't it? This is all one big show of dominance over him?"

She pulled her underwear a little higher than she really had to, so that the stained crotch pressed hard enough against her pussy to show a clear outline. When she turned to leave, they were wedged far enough up her crack that half of her ass cheeks were visible.

"I just hope you can handle the consequences," she grins, turning around at the door to wink at John once before leaving.

"Shit..."