Do I confront her, break them up, or leave it be?

My daughter is 17. She is not allowed to date. Our rules are no dating until after high school or 18+. I found out that she has a boyfriend of 9 months. I discovered this because I found her social media. So I made a dummy account and followed her pages. It seems that all the times since told me she was with friends or at work, she was with him. I clicked on his page when I saw she tagged him and he had a photo of the both of them laying in his bed. She had the blanket completely covering him but he was uncovered & topless. I was really surprised by what I saw. The only reason I have not mentioned anything yet is because my daughter currently has corona (This is day 9. She takes vitamin c + zinc tablets and ginseng tea. She's slowly recovering but I guess it'll be a while. I'm the one who passed it on to her accidentally.) I don't know how to approach this at all.