By Meghan Overdeep
Updated Dec 14, 2015 @ 11:15 am
Kendall and Kylie Jenner - Cool Aunts
Credit: kyliejenner/Instagram

Kendall and Kylie Jenner have made an official bid for the position of the "cool aunts" of the family. The youngest Kardshian-Jenner sisters were on hand to flaunt their coolness and celebrate the birthdays of two members of their clan's next generation. Sister Kourtney's sons Mason, 6, and Reign, 1, Disick share a Dec. 14 birthday, which the family marked with a joint bash this past weekend. Kendall and Kylie wore matching Yeezy camo trenches for the affair, which was full of opportunities to squeeze and kiss little Reign.

"The cool aunts," Kylie wrote alongside an Instagram gif (above) of her and Kendall holding the smallest birthday boy.

Kylie posted another gif of her going in for a kiss from Reign, who looks adorable in a denim jacket and oversize beanie. "I love you baby angel" the reality star, 18, captioned the clip.

Kendall posed for a solo pic with Reign as well, which shows her holding her nephew on her hip while looking at her phone. "Me as a mom," the Victoria's Secret model, 20, joked in the caption.