<prompt> Human: Not sure if this is the right subreddit, but its the first place I thought of asking.TL;DR: roommates girlfriend moved in to his room, pays for utilities, doesnt pay rent. Should she?Background:My roommate, X, and I have been living together for a couple of years now. Our girlfriends have always come over to stay a night or two, and it has never been a problem. However, his current girlfriend Y has been living with us for months now. She was staying with us most every night for a month or two, then got kicked out of her old place, which led to her moving in. This was never discussed with me; things changed very little before she moved in and after.We currently have a 42 house with a two car garage, using two bedrooms for ourselves, and two as storage rooms. I feel it would be fair for us to all evenly split the rent 3 ways, even though she sleeps in his room and uses his storage room for some of her storage needs.Up until 2 months ago, X and I split everything 5050 with no issues from me. He pays for the Internet services, as he has the master bedroom and both spots in our garage. I have one dog. Y also moved in her dog and two tortoises who live in the backyard. She has a storage unit for all of her other items that wont fit in our house. As of two months ago DecemberJanuary they now pay for 23 of the utilities; in addition to normal utility use, she does laundry for her job at our home, and has a heat lamp for her tortoises which is now constantly running to ensure their health.Question:Though the utilities are now being split appropriately, should she be paying rent? X claims that Y helps him with groceries, house supplies, yard projects none of which truly affect me, though having a nice yard is nicer than I anticipated, and other decorations for the house artwork, candles, things to make it feel more like a home is Xs words. This, combined with the cost of her storage unit, is his rationale as to why she should not pay rent.I argue that, storage unit or not, she has been living here rent free for at least 5 months. Paying for utilities is nice, considering she uses more than either he or I do, but paying for rent seems more fair. Her parents live nearby, so its not as though she would be completely homeless had he not offered to let her live with us. She uses our house as her mailing address, as well, which further makes me feel like she should pay rent.I proposed that X and I switch rooms, giving me the master bedroom. I would clear out my storage room, allowing them the opportunity to have two storage rooms so Y wouldnt need to rent a storage unit. X doesnt like that idea.X proposed that he would be willing to have her pay minimal rent, anywhere between 50-100. While this is a nice gesture, I still dont think it fully covers the fact that she has more animals and spends more time at the house than I do.So, rpersonalfinance, what do you think? Am I right for wanting a split, or should I buck up and shut my mouth? Should I fight for an even split, or should I take what he offered?Notes:- We all get along fine, minus this conflict. I enjoy her company, our dogs get along fine. She is a good person with a steady job not a crazy druggie or vagrant looking for a handout. This is not personal.  <response>: And is her permanent presence in the house a violation of your lease agreement? 