North West and Penelope Disick had Khloé Kardashian all to themselves on Friday. The proud aunt shared new memories [2] from the fun night with her nieces on Instagram. Even as Penelope hung on her back, Khloé managed to capture the trio's joy with a smiley selfie. Minutes before, Khloé posted a short but sweet video that shows North and Penelope laughing with abandon and shouting while playing under a sheet. "Like a diamond," Khloé wrote in the caption, referring to what the cousins are heard saying in the clip.

The night also had its share of relaxing downtime — at one point, the trio watched the animated movie The Book of Life.

This isn't the first time the cousins' cuteness made its way to Instagram. Earlier in July, Kim Kardashian shared frame-worthy snaps [5] of daughter North and niece Penelope. After you check out their latest Instagrams, relive North's most adorable moments — so far [6]!