<human>: Hey guys

I just started living with my housemate [20F] this school year. For the first 3-4 months or so, everything was fine; she and I weren't close because she was always with her then-boyfriend and would spend most of her time at his house, but we were friendly to each other. They broke up around 2 months ago and she got with her current boyfriend 3 weeks after.

In the beginning, I and my other 2 housemates [both 19F] were fine with him sleeping here. Our apartment is on the small side, so I was a tad bit bothered by him sitting in our living room for the majority of the day, but didn't bring it up as I didn't expect this to escalate any further. 

Except it did. They've now been sleeping in our living room for over a month. He spends at least 18 hours of the day in our house. He's gotten comfortable to the point of buying a TON of groceries and loading them into our fridge. He uses dishes/kitchen appliances and then leaves them, unwashed, for days. He plays music (loudly) early in the morning and late at night. There are a host of other problems that I won't get into. Even with all this, he's still a nice guy, just inconsiderate imo.

My problem is this: how do we confront her without starting a fight? She's the type of person to get defensive and angry as soon as what you say sounds like an accusation. Furthermore, she's been in kind of a pissy mood ever since they hooked up (e.g. snapping at us for very trivial reasons, talking to us in a condescending tone). The catch is we all signed a lease to live together next year, so I'd like to avoid a fight if at all possible.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: My housemate's boyfriend has practically moved into our small apartment, how can we ask her to have him over less often without causing a fight?