How do I tell people 🤦🏽‍♀️

So my boyfriend had a child with another woman who has been so bad to him she has held his child from him just because he moved on.... We have been dating for a year and it’s been the same..... So first my boyfriend was 16 when he had his first and I was 18 19 when I had mine we have two different kids from two different people but now we are having a baby together 🤰🏽So the major thing here is how do we tell his parents with all that’s going on🤦🏽‍♀️ Sadly his baby mama did something even worse recently and I’m scared that it’s gonna take from our moment we are 19 and 20 now and I’m scare that people will already be upset because we’re young with 3 kids but now THIS 😖 As soon as she heard she went and acted a straight fool.... ugh advice please?! What would y’all say or do and how would you break the special moment? How long would you wait? And how would you ease into it???