There was a lot of arguing on Sunday’s episode of Keeping Up With The Kardashians as Kim and Kourtney went to war over fashion.

But the sisters found time for some joy, too, as they relaxed by the pool at their Palm Spring, California home.

In one scene, Kim, 38, wears a pea green ʙικιɴι that makes the most of her curves as Kourtney models a pink two piece by a swimming pool while Khloe takes snaps.

Kim – who weighs 118lbs thanks to a low-carb diet and weight lifting – looked slender in the little two piece as she added a beige wrap and some funky sunglᴀsses.

Kourtney had on pink two piece that consisted of a bandeau top and high-cut briefs. Both had silver studs everywhere.

At one point Khloe, dressed in black workout clothes, was seen taking steamy pH๏τos of her older sister as Penelope looked on.

The ladies are finally learning to chill out over a tiff.

Kim had criticized Kourtney for the fashion options she had for her 40th birthday bash.

The wife of Kanye West did not like any of the outfits that Kourtney’s stylist had pulled and said she needed to be Sєxier.

The Poosh founder, who was nervously preparing for her 40th birthday party, had trouble choosing an outfit.

Kim made it worse by criticizing everything she considered wearing.

The eldest then put down Kim’s look for the spring Met Gala, which irritated her sister, leading her to accuse Kourtney of trying to co-opt her style and relationships with designers.

‘I said, ”You’re going to school to become a lawyer and help the world, and these are the kinds of problems you have?”’ Kourtney recounted to their sister, Khloé Kardashian, 35.

Kim jabbed back by text message, calling her ‘a miserable human being.’

‘You all of a sudden turned into such a humanitarian and talk about the world’s issues, when you’ve not contributed one ounce to the world,’ she pointed out. ‘You f***in’ fake humanitarian ho.’

Kim got even more incensed as she recounted the incident to their mother, Kris Jenner, 63.

‘I actually f***in’ do s*** for the world, and you f***in’ fake it all day long, and act like, ”Oh, there’s people dying, Kim”,’ Kim told Kris, imagining what she’d say to Kourtney.

‘And what the f*** are you doing about it?’ she added.

‘Shut the f*** up.’

Kim went to Kourtney’s house to help her choose an outfit for her birthday party.

‘Forty is like, the most important year,’ Kim considered in a confessional. ‘This sets the tone: Are you going to be old, or are you going to be young?’

She immediately hated the clothes that Kourtney’s stylist Dani offered her, rejecting outfits with too-тιԍнт tops, feathers, belt buckles and heavy sequins.

‘My 40th birthday, I want to look, like, the best ever, and I just think you can’t go, like, mediocre like this,’ Kim reflected. ‘Nothing is jumping out to me. Nothing is special.’

‘This is so typical Kim, to just hate on every single look that I have and tell me that everything is ugly,’ Kourtney complained.

‘She doesn’t have to be so hurtful, especially when I am so overwhelmed.’

‘You need to be a bit Sєxier,’ Kim told Kourtney, who was trying on a see-through mini-dress.

Kourtney took her own digs when she later watched Kim’s fashion makeover.

Kim had FaceTimed to show her the outlandish Thierry Mugler outfit she was preparing for that spring’s Met Gala in New York City.

‘I was thinking about wearing this to your 40th birthday party,’ Kim teased Kourtney. ‘What? Is it too dressy?’

‘Are you coming as Nicki Minaj?’ Kourtney asked.

‘This is Cher, honey,’ Kim answered, stroking white beads in her hair.

‘I would say it’s October 31st,’ Kourtney affirmed.

‘Don’t insult me!’ Kim faux-shrieked.

In private, Kim grew angry: ‘I’ve been planning my Met look since last year, and she was so rude in front of the whole Mugler team… it’s all super-embarrᴀssing.’

The Mugler manager told Kim that Kourtney’s stylist had been trying to get their dresses, too.

‘For her to not only try to use the same designer but then to be so rude, it really hit me the wrong way,’ Kim declared.

Bizarrely, the stylist had also scooped up a bunch of Rick Owens tops that had been fashioned after a look Kim wore to the CFDA Awards in June.