Go for it all

"Luna, you are now my devoted, sexy, obedient girlfriend. You love me unconditionally, and nothing I do is wrong or immoral. In fact, I can't do anything wrong or immoral in your eyes. Anytime you see me talking or flirting with another girl, you know it's what makes me happy so you will accept it. Every week, you want to do study dayes with me. You feel as though if you do not go on study dates with me our professors will view you as a dumb blonde bimbo. Finally, if you do not suck me off once a week and swallow my cum, your hair will fall out and you will become an unattractive, bald hag."

Okay, he would admit that last one was just for fun. But Luna was a score. If the spell worked, he would have an attractive piece of arm candy.