Would you be comfortable with your partner using dmt ?

I’ve never done it and smoke weed maybe twice a week. My bf used to smoke all day every day but I got him to slow down a bit when he started going too far down these conspiracy theory rabbit holes - causing him to start making irrational decisions. Recently he now started using dmt and I wish he wouldn’t. I’m scared it’ll mess with his head if he does it too often. Would it be wrong of me to ask him to stop? Or limit it to a few times a year?