Mark her to obey on sign

She is marked with a womb tattoo that glows and projects itself through any fabric and clothing. You let her free, but soon she will find out the evil predicament she is in. Every time she sees the sign, she feels a desperate urge to suck and fuck the first guy she sees. No control whatsoever. Soon, the knowledge of how to make her anyone's slut spreads from town to town. She is doomed to be a slut on command.