Kourtney Kardashian wanted to skip her party and be "alone" after a huge row with Kim

During a wardrobe fitting at their home, Kim told her sister: "Nothing is jumping out to me. Nothing is special. What's the vibe here?"

Kourtney tried on a sparkly little black dress, which was detailed with feathers but Kim didn't like it.

She told her: "Absolutely not. You're not a ****ing peacock."

The arguments about dresses and designers continued and it left Kourtney feeling "overwhelmed" and demotivated.

She cried to the camera on the latest episode of the family's E! reality show: "I just feel overwhelmed with my birthday and everything. I don't feel like myself. I just want to go away somewhere and just be alone."

Meanwhile, the 40-year-old reality television personality previously confessed she is "anxious" about turning about 40.

She said: "I do think that turning 40, like it almost makes you analyse like where you're at in your life. It's just giving me anxiety ... I feel like I want to cry. It gives me anxiety."

And a source had recently revealed Kourtney is having "fun" with her dating life but she's not interested in settling down at the moment.

An insider said: "Kourtney likes having someone in her life. She loves being a mom and that's always her priority, but she can get lonely too. She goes on dates and has fun, but she doesn't have a boyfriend and would never call any of these guys her 'boyfriend.' She's been through a lot, personally, over the last decade and feels she's come out stronger and happier. So she's excited about turning 40 and what's to come. When she talked about turning 40 a while back, she didn't seem too excited. Turning 40 is a big deal. But instead of seeing it as something negative, Kourtney turned it around and she seems very excited about her life just in general. She feels great about many things that she has accomplished so far. She is very excited about Poosh. She has been very focused on it. She has a small team that helps out, but she's putting in many hours making sure her site is fun, educational and features brands that she loves."