new guy in my life

ok so if y'all have been reading my other posts about my shitty ex who fucked my cousin well now I'm kinda talking to this new guy, well we hung out a time or two and I think I want to give it a chance he seems really nice but he's been to rehab for drug use a few months back and idk him like that quite yet to know if he's still doing drugs I know he smokes weed I'm ok with that but like how do I like try to find out if he is? I don't wanna just come out and ask cause I don't think he knows I know that he's been to rehab. I don't wanna waist my time if he is on drugs still