Roommate wants to live with me, but I want to live with my boyfriend. What to do? Suggestions.?

My B/F told me today that his lease will be up on July 25th and that he will finally move in with me, after 4 years of dating!!!! The problem is that I have a roommate. She moved in with me in March and already doesn't like my duplex because of the neighbors that live downstairs. She has been bugging me to set up times to look at other places because our lease is up in June and she ALREADY wants to move. I dont know if she is cool with it, it sounded like it at first, but then she said things like, I know about this one bedroom Justin could look into, it's really cheap. She did ask me how much I really wanted to live with him, and I told her I've been waiting for a long time and yes I do really want to live with him. I do most of the cleaning and ALWAYS do the dishes, so I want to finally do it for someone who I really care about and not her. (I mean I like her and everything) I found a place for all of us, we'd each have to pay $333+utilities. She is worried about us breaking up and