How to tell soon to be exhusband

Me and my husband officially separated back in September, I got pregnant in October. Clearly not planned, but I’ve came to terms with it and am happy/have a supportive family. I am with the guy I’m pregnant with but not rushing it, me and my ex have a almost 2 year old daughter together. I’m living with my parents and have my daughter most of the time and will not be moving in with my boyfriend until I feel my daughter is ready for that. How do I tell my ex? I’m 24 weeks and he still hasn’t noticed(if he has he hasn’t said anything). He can very cruel when he’s mad and run his mouth. I really don’t want an argument or to go back and forth with. I need a way to tell him, that’s straight to the point and covers everything, to clear the air of it.