Sounds to me like she has approached him quite sensibly and aired her worries to her man quite well actually. Of course she's going to fret about him as she has been told about the dangers of drugs before and has based her judgment on that. I genuinely believe that her man doesn't want to take drugs again, at the moment. I often have those same feelings of epiphany but it doesn't mean there will never be a time (for me), it just means that I can happily forget about them and enjoy/make the most of being sober/straight whenever it occurs. I know other people struggle with that sometimes but it sounds like her fella's quite good at it and is genuine (at the moment). He's a lucky man to have somebody that cares about him to worry so much but as I firmly believe, taking them isn't a problem, needing to take them is. I'm sure you'll know if he ever crosses that line and if/ when it happens, then chuck him. Right now, it just sounds like he's experimenting a bit and there's probably no need to stress too much.