Stop them for a while

Jack put them both in trance. He had to admit having daughters was sexier than anticipated.

"Okay, you two. I have another client soon, but when I wake you, you will be my daughters for all eternity. Understood?"

Mona and Lana nodded.

"And here's the fun part. You're gonna bury all memory of your past lives deep down where you can never get them back. As far as you are now aware, you are both 18 and my daughters."

Jack sent them to the back room, where they then woke up.