The prosecution: Matt Natalie turns into a slob the minute Mum and Dad go on holiday. I come home to flies buzzing around in the kitchen My younger sister, Natalie, is a sneaky one. When she’s at home with Mum and Dad she’s very tidy, but when it’s just us in the house her true self comes out. Natalie is 19 and is in a part-time apprenticeship, while I am 25 and work full-time, as do my parents. They are both teachers and get more time off than Natalie and me, so they often go on holiday for weeks at a time and leave us at home. My mum says that in their absence I need to look after Natalie and keep the house tidy, but once they’re out the door I have little to no jurisdiction over my sister. Freed from their watchful eyes, she turns into a slob. Mum can be quite strict, so maybe Natalie sees their holidays as a chance to have some time off, but I find it hard to manage. It is mainly a kitchen problem. Natalie will let plates pile up for days without rinsing the food off. We have a dishwasher but she is too lazy to stack it. I’ll come home from work and there will be flies buzzing around. It’s not nice. She forgets to wipe down surfaces after cooking breakfast, and has left unwashed pans out all day. If I tell her off she says: “You can’t tell me what to do”, and leaves the kitchen in a huff. She also gets annoyed if I do a food shop without running everything past her, but I just want to get it done. She refuses to help out with things like taking out the bins, too, saying it’s a “man’s job” – and that I should do it when Dad isn’t home. I think she just likes to make excuses. I have told my parents what she is like when they’re not around, but Dad doesn’t believe me because Natalie is a daddy’s girl, and Mum simply tells Natalie to ensure the house is tidy before she returns, which it always is. Annoyingly, Natalie always makes sure everything is cleaned up about 30 minutes before they walk through the door. If I complain in front of them, she denies it was ever messy. I sometimes feel like I’m being gaslit. The defence: Natalie When our parents are away, I like to live the way I want. And I always clean everything up before they get back My parents go away a lot during their school holidays and I definitely like having a free house. Although it’s not really free because my brother, Matt, is around. He has got two modes: super relaxed and barely around because he’s working or with his friends, or negative and moody because he’s hungover and stressed. There is no middle ground with him. Last summer my parents went to Asia for two weeks and Matt was insufferable. He would come back from work and moan if there were a few crumbs on the counter or a plate in the sink. I was home more often last year because my apprenticeship was fewer hours, so it was natural that I created a bit more mess. But it’s not as bad as Matt makes out – I just prefer to let things build up and tidy it all up at the end. I leave pots and pans to soak for a few days before washing them. Our parents would tell me off for that, but when they are away I like to live the way I want. Matt isn’t even that tidy, but when our parents aren’t around I think he feels as if he has a bit of power over me. But if that’s the case, he should use it properly. Our parents leave us a budget for food, but he never asks me what I want when he does the shopping – he just gets the usual stuff and all the things he likes. That’s pretty annoying. He should take me into consideration if he wants me to do the same for him. And I stand by the fact that taking the bins out is a man’s job, and Dad agrees. When he got home after one holiday he told Matt to step up to the task. Girls don’t take bins out: that’s just a fact. This summer our parents are going to South America for three weeks, I’m off to Spain, and Matt’s going to Croatia. There will be 10 days when Matt and I will be in the house alone together. Because he grassed me up to our parents last time, I’ve decided to make a little more effort to keep the kitchen clean. But only a little. He needs to take a chill pill. The jury of Guardian readers Should Natalie pick up after herself? Natalie knows she’s in the wrong, she mentions being “grassed up” by Matt. I think she doesn’t want to contribute as she feels entitled as the baby of the house. It’s time to grow up and behave like her parents are there. Frank, 65 As a young adult, Natalie should start taking responsibility for keeping the house clean. But that’s hard to do when Matt is deputised as a stand-in parent. They should agree on cleanliness standards while their parents are away and Matt should treat her as his housemate, not his ward. Kyle, 35 Natalie is guilty. If flies are buzzing around the dishes, it means they’ve been out for far too long. Also, girls can (and should) also take the bins out in the 21st century. That said, Matt needs to listen to Natalie’s requests when doing the shopping. Perhaps she might then be more inclined to clean up after herself. Ashley, 29 Natalie lost me at bins being a man’s job. If she wants gender stereotypes, she should have the house clean, look pretty and have dinner on the table for the all-powerful male of the house, even if he is just a stand-in. Let Matt enjoy freedom from your parents as well. And the flies. Alison, 52 They are adults and need to start treating their home and each other that way. How about having a grown-up conversation? Wipe the slate clean, forget about “blue” and “pink” jobs, and figure out how you are going to live together. Then stick to it. It’s only 10 days! Chris, 45 Now you be the judge In our online poll below, tell us: should Natalie do more to keep the house clean when her and Matt’s parents are away?