Scott Disick Calls 'Bulls**t' on Kourtney Kardashian's Reason For Why He Wasn't Invited to Khloe's Birthday

Scott Disick on 'Keeping Up With the Kardashians'

What's a party without Scott Disick?!

In a sneak peek clip from an all-new episode of Keeping Up With the Kardashians, the 34-year-old reality star gets into an argument with his ex-girlfriend, Kourtney Kardashian, after he learns he wasn't invited to Khloe Kardashian's birthday bash.

"F**k, I didn't even get invited to her birthday," Disick says during a heated conversation with Kourtney and Kim Kardashian West. "And I'm family. That was really sweet. That made me feel really good."

The clip then jumps to a close-up of Scott, who says there's only one person that would have gotten him "not invited" -- Kourtney.

MORE: Scott Disick Says Dating After Kourtney Kardashian Is 'Not Fulfilling'

"I highly doubt that Khloe was like, 'The last person I'd want at my surprise party would be Scott,'" he explains in a sarcastic tone. "It's cool. Honestly, I called my sister and I hung out with her the whole night. And then, actually, I called my mom after and was [like], 'Hey, mom. Do you want to come over? Because I'm feeling a little down and lonely because the family that claims I'm still blood even though we're not together still doesn't invite me to a surprise party.' But I really felt good about it."

As Scott continues to make his case for why he's so upset, telling Kourtney he doesn't "get it," the mother of his three children tries to end the conversation by fabricating her side of the story.

"I didn't want to have you coming to the birthday and be photographed going in," she says, later admitting that's not what she "really" meant. "I'm a little bit caught off guard. I was trying to be positive. I didn't want to say I just didn't want you there. So, if I can't say anything nice, I just won't say anything at all."

Unsurprisingly, that doesn't go over too well with Scott.

"That's all bulls**t," he replied. "It's funny to realize just how fake you really are though."

WATCH: 'KUWTK': Kourtney Kardashian Reveals What First Attracted Her to Younes Bendjima

Keeping Up With the Kardashians airs Sundays at 9 p.m. ET/PT on E!

Hear highlights from last week's drama-filled episode in the video below!

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