I wasted many precious moments I can never get back second guessing if my BF was using, arguing over drug tests I didn't need to see to know the truth, then arguing over if it was a pass/fail...you get the idea.
Rehab was followed by chronic binging every 2-3 months (3 x), then stretched to almost 5 months, etc...more precious time wasted fighting over the relapse signs, the relapse, etc.
His DOC is coke, crack & oxy's.
I've found that the relapses were long preceeded by a lot of behaviours that were really reminiscent of the active addiction phase.
Do you want this for yourself? If he's going to relapse he is, all you can do really is focus on what your line in the sand is.