I find it hard to trust my bf

I need to talk to someone about this and need other peoples opinions so I would really appreciate a response🙈

So me and my bf have been going out for about one and a half years. I can honestly say I've loved this guy through fire. We've been through some pretty rough times (he cheated, we broke up etc,) and now its been going better than ever. Thing is hes still in his last year of school and I'm at uni. He's in boarding school and shares a house with girls which does stress me out a lot. But anyway, his graduation party is coming up and he wants to do MDMA which I literally cant handle because he always loses control on drugs and my first relationship with a coke addict has traumatised me. Worst part is the girl he cheated with will be there too...I just want him to have a clear head...is it so wrong of me not to want him to take MD?

Update: thank you all for your responses. I just dont know though like I cant forbid him to do things and live his life like a relationship is also about letting someone do their own thing.