Living with roommates means navigating a constant balancing act between fairness and flexibility.

When one housemate decided invite his sister for an extended stay without asking, tensions over who pays what started boiling over, big time.

Read on for the full scoop.

AITA for asking my roommate to pay extra rent for his sister staying with us?

So I (24M) rent a house with four other guys.

One day, one of the roommates came with unexpected news.

Recently, one of the housemates let it slip that his sister would be coming to stay with us from June 1 through mid-August.

He never asked permission but happened to mention it to my roommate, who told me today.

The other roommates were understandably upset about this.

My roommate and I were upset and messaged our group chat to say that she should pay her share of utilities plus a flat fee for rent since it will be like adding an extra roommate (an extra person using the living room, bathroom, kitchen, fridge, etc.).

He got upset and said I’m an AH for asking and that she’d pay utilities but not rent.

So the roommate fires back with his grievances, which aren’t really even comparable.

He brought up how my girlfriend comes over on weekends (but doesn’t sleep here because I share a room) and said it’s not fair since she doesn’t pay rent and utilities.

Granted, when my roommate goes home, like one weekend every other month, she will spend the weekend, but to me that’s not the same.

Not to mention this roommate was already on thin ice with the rest of the household.

I especially didn’t like that argument because over the last six weeks, he’s had three separate friend groups stay at our house, and two more people coming this weekend.

So AITA for asking him to pay rent for his sister?

A roommate agreement only works when everyone respects it.

What did Reddit have to say?

He could probably find language in their lease agreement that would support his point.

This roommate’s argument doesn’t even come close to holding up.

This commenter sees right through the roommate’s façade.

This user encourages him to not lose sight of the real issue at hand here.

This guy wouldn’t even give his fellow roommates the courtesy of a proper discussion.

Sharing a house means sharing responsibility, not handing out free rides.

If you liked that post, check out this story about a guy who was forced to sleep on the couch at his wife’s family’s house, so he went to a hotel instead.