Boyfriend making an impossible request?

When you are in romantic relationship you in it with them and their whole relationship. Put yourself in his sister's shoes. You have two people that you need to protect, so you will do anything and go anywhere to save them. Now put yourself in your bf's shoes. He is scared for his family and does not want anything bad to happen to them. He also has a chance to help someone he loves, see he invites her to live with him. My point is, no one is trying to cramp you. You are being unconvinced only. You are not fleeing for your life or the life of your kids. You are not worried about your sister and her kids dying of cold and starvation in a nuclear wasteland. I think this could be great for you. I was honestly laughing when I read this. I think you could learn more about motherhood and your bf from this. People always say life is what happens when things don't go as planned. That said, I think you are fully entitled to say no because this will be a miserable situation if you are forced to do this against your will.