opinions please! Should I be concerned?? 🤔

So today my bf asked me to leave early because the mother of his daughter was coming over... I've never met her or the baby, but there are good reasons for that. I'll meet them when he is ready. He says he wants me to meet her so that we can all get to know each other because eventually I'll start to be around his daughter. Which is something I respect because I would want her to be comfortable with me being around her daughter. It was just unusual to me that he asked me to leave so early because she was coming over. He's never said anything about her just randomly stopping by on her way to work before. Should this be a concern or should I just trust him? He explained that their relationship is friendly and no hard feelings towards each other. He just didn't want her to meet me like that at his house because he doesn't know how she will react 🤔