He lied, feels bad but I don't want him near me

I could be overreacting but I'm just sad.

My boyfriend's mother is a recovering addict, we'll she claims to be "recovering." Her and my boyfriend had a very bad relationship when she was messed up all the time. She finally went to rehab but a few months later she was prescribed adderall, again.

I'm okay with him taking adderall, my problem is he is taking it from his mother, a "recovering" addict. He cried over her being a junkie and now he's taking pills from her? I don't understand it.

Last week he was looking for something and I asked what he needed to find. I saw a little pill near the area he was looking for something and he said "Oh I dropped my lighter" while grabbing the pill very quickly. He was hiding the fact that he got adderall from his mom and lied about it being his lighter that he grabbed...I'm not dumb I saw the pill. I told him I don't care that you take pills it's where you get them from. Don't enable her addiction.

So tonight I slaved over dinner and made him dessert (which is rare to make dessert). I walked into the bedroom and saw he was outside on the porch. He leans on the bedroom window whwn he talks outside, so I can hear almost. I'm guessing he thought I couldn't hear him. I heard him say to his mother "give me an excuse to come over there so I can get it, something I can tell her (me)."

I walked out there immediately and told him "I heard that." He came inside and looked terrified that I had caught him. He lied about this last week and I told exactly how I felt about it. I'm just sad that he can lie so easily about this. Again it's not the pill it's the fact that he is enabling her addiction for his own selfish needs.