Confused as fuuuuuu*k

Ok let’s get this started..

so my boyfriend of 3 years has a twin sister. She’s cool and i have no problem with her but my boyfriend and I recently moved into together and she has been blowing up his phone and telling him that he needs to move back because of some bs reason like his mom wants him home or whatever but that’s not the case because his mom and I talk literally everyday since I’m pregnant and she’s been helping me plan the gender reveal. But back to the main idea yesterday I was on my boyfriends phone looking at crib and she sends him a text saying “she’s just playing you, she has never loved you. I need you back.”

Ok first of all WHAT! I immediately took him the phone and he was even surprised. He said he’s going to talk to her but what do I do? Do I just not tell her anything? I’m actually kinda worried that she’s going to be weird around my child as well.

UPDATE::::

Ok I know this was quick but I had a very deep and serious talk with him about it and he was actually really weirded out and angry about that text. He had her come over our house and they spoke for what seemed like 10 hours but it was really only like 3 or 4 and when they finished she came and apologized and said she just missed him and was having a hard time accepting that he was living somewhere else. I mean I understand but she still shouldn’t have texted him that. But I guess it’s fine now.