How to approach?

Victoria
In the year that I've been with my boyfriend he has done coke three times. He came home from work the other night and had told me that the dishwasher gave him some. He said he just wanted me to know he had it because he knows how I feel about him doing a harder drug such as coke. His family has a line of drug addiction being his mom, brother, and grandma. He could tell it made me uncomfortable but he didn't do anything about it. How can I bring this to light without seeming like I am trying to control his life? I don't know how to talk to him about it/even bring it up.