Bio Mom doesn't want me at visits

Ca
I have raised my stepson with the bio dad since he was a few months old. He is now 4 years old, and after years of missing her supervised visits, not contacting her son, and drug/alcohol/violence abuse, the bio mom decided she wants to step in now. We met up with her the other night and we told her that this was her last chance; if she didn't step up and be there for her son then I was going to adopt him because he knows me, loves me, and has chosen to call me "mom". She surprisingly got upset and decided that she wanted to start being the mom. I was happy she said she was going to be there for him although we both highly doubt she will go through with it. I have always been polite and civil with her... but last night, she texted my SO this: "If I'm going to start seeing my son I don't want your GF there, she has nothing to do with this I just want to be close to you again and I feel like she's holding me back. Can you sneak away from her and let me see you guys? I promise I won't tell anyone if you don't tell her" I laughed because my SO called her and was like "lady you're crazy. I would never do that it is important that the kid sees us all together working as a family and not sneaking around having private conversations. There's no need for that, and whether you like it or not SHE is here she has always been here and she's not going anywhere." His ex cried and was all upset because she feels she can't have a visit with her son if I'm there. WTF? Really? I get it if I was rude or something but we have always got along great when she showed up for a visit (on the very rare occasion she actually showed up). Why are you worried about who is there when the ONLY one you should be concerned about is your kid.. we believe it's imperative that we are all there as a team for the kid, there's no reason that anyone should be excluded from visits unless they are interfering with the time she has with her kid. If this was a legit concern of hers I would respect that but I feel a spark of jealousy from her.. we both feel she needs to get over it and focus on the kid. What do you guys think? 

Vote below to see results!