Thoughts?

So my boyfriend and I have been together for two months. His ex has a kid and it's not his. But her daughter calls him daddy. (They only dated for two months). His ex calls him and texts him constantly begging for him to come over and help her put stuff together as she is dislexic. He does help her but only when I am working as he wants to spend time with me at that time. She hates me because she's still in love with him! He says and swears they're just friends but when I had a miscarriage, he told her. And said I'm not going to tell anyone else because it's none of their business. Okay? So how is it any of HER business?! I've never met her or her daughter. I have seen pictures. They also used to sleep together. I try to tell him it bothers me how weirdly close they are but he just tells me to drop it because they're just best friends. I trust him but I don't trust her.