He’s a recovering addict and she would help him access drugs
He just informed me he’s spending it w/ her drinking bc she isn’t available another day
Turned his location off after our discussion

So he's going to hang out with her one night per week to drink with her OR to access drugs and do drugs with her?

What does it me to "turn off location"?

Sounds to me like he's placing his addiction above you, which will ALWAYS be the case.

Sounds like a no-win situation for you, sadly. I would think twice about moving forward in any kind of relationship that prioritizes drugs and a roommate over seeing me.