[18M] [18F] My girlfriend keeps eating my eyebrow hair

My 18F girlfriend keeps licking and eating my eyebrow hair. I know, its as weird as it sounds. She has essentially removed all of the hair in my left eyebrow and left my right one looking incredibly patchy. I have mentioned I didn't like it and she continued anyways. What should I do?

I really love her, I do not want to break up with her over this. She used to be normal until she joined an "eyebrow eating?????" discord group We have been together for 3 years at this point, and I want to spend the rest of my life with her, but I cannot do that if my eyebrows are balding. Plus, recently she bought a really expensive shampoo because she said it "makes them taste better"? What the fuck???

This has become her obession, and it's destroying our relationship. I am worried for her and scared.

Thank you for your help in this awkward situation .

EDIT: For everyone asking I don't let her she mostly does it when I sleep and since I am a VERY deep sleeper she rarely wakes me up while doing it.