Step son bio mom is pissed at me

My step son came over for the weekend yesterday. He was acting strange. When I was cleaning the bedroom he came to me to say he needed help. Of course I'm gonna help him. He said he hurt his balls really bad on his bike. Like really bad. He said he's been peeing blood. I asked how long has this been going on. He said A FEW DAYS!!! I asked why he didn't tell someone right away and said he felt like he had no one he could. I asked if permission to talk to his dad and bio mom and he didn't want me to at first but the agreed to it. I told his dad and his dad told bio mom and we went to the hospital. Bad new... He did have to lose his right testicle. Good new.. He will be okay and can still have children if he chooses to. His mom was really mad though at me because he told me instead of her. She actually goes to scold him after the doctor leaves the room. He just found out he's gonna lose a testicle and then he was being yelled at by his mom. She turns her anger on me again and told me to remember my place and I'm not his mom I'm just a whore her ex met at the movies. She got so loud and was making my step son so upset that they had to remove her from the hospital, so she couldn't even be there when he got out of surgery and guess what, apparently that was my fault too 🙄

Edit: For the person calling me a homewrecker. Wow. Yeah I sure wrecked their home. Not like they had already been divorced for 3 years when we met🙄. Some of you women be making the dumbest assumptions with NOTHING to back it up. Also like to add when me and my husband first got together his ex was engaged. Wow I'm such a homewrecker