She leaves you for someone else

You caress your body, and give your crotch a good scratch.

"Wow, this certainly feels different," You remark. In your head, it's like you thought those thoughts yourself, even though you know it's your mother doing it all.

You start recklessly throwing your clothes off, ready to engage in male pleasure... and stop.

"Hmm. You need to work out, son. Maybe I'll sort that out - but right now, I want some good action, and you would just take too long."

You feel an outward bursting sensation, and Megan walks out.

"I'll be back for you, dear - oh, and just in case, I'm cursing you to be unable to let anyone know about this in any way, shape or form, and you won't be able to leave the room."

She then trots out, leaving you naked and confused.