Not a pleasant surprise. Kris Jenner is left reeling in Keeping Up With the Kardashians' Sunday, June 26, episode after she learns secondhand that Rob Kardashian proposed to Blac Chyna.

In the E! series' preview clip, Jenner, 60, tells the camera that her only son, 29, didn't let her know that he would be popping the question to his girlfriend, Chyna, 28, and that she found out about it on the internet.

"I wake up to a gazillion text messages, which is never good news," Jenner says. "And I'm reading through them and realize Rob got engaged last night. He got engaged! And it's sort of coming out of left field. Like, I think I'm just in shock."

Jenner adds, "To hear that Rob got engaged through social media is a bit disappointing, to say the least. He should have told me first or even talked to the family about it or mentioned it to his sisters. But I had no idea."

In the show's Sunday, June 19, episode, Khloé Kardashian found out about the engagement through social media during the family's trip to Vail, Colorado, which Rob had opted to skip. Khloé called her brother a "f--king p--sy" for not telling his sisters that he was planning to propose.

News of the engagement first broke on April 5 when the couple of two months posted pics of the makeup artist wearing her 7-carat diamond engagement ring.

A source told Us Weekly exclusively that Jenner informed Rob that he's "making a mistake" by moving so fast with Chyna. The model announced in May that she and Rob are expecting their first child together.

Watch the emotional clip in the video above.

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

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