After getting her very revealing clothes back on, Janet had a quick thought about a way to make the evening very interesting. She got the pen out and began to write "I will know anything which is written with this pen" as a way to ensure her little plan goes in a way that she can manage.
"In 5 minutes this pen will appear in Daves hand and he will keep it until I change back, but when using it he will always be making changes that are sexy in nature involving the two of us"
Janet was idly fondling her recently enhanced breasts as she imagined what Dave would do to her with the magic pen, now safeguarded. The thrill of losing so much control was getting to Janet and she couldn't wait to see what a pervy version of her old self would do.