My son had some terrible relationships. An active addict is incapable of having a healthy relationship, but that doesn't stop them from trying.
I always stayed out of my son's business. My "deal" with myself, my son and any girlfriend who would ask was "I'm not going to be an information line, but I am never going to lie for him either. I would just as soon you don't ask because you won't like the answer." They didn't bother asking, which is good because I never ever wanted to be included in their relationship mess.
Stay out of it, you have enough just handling your own emotions right now.
It's just not our business what choices they make.