Kim Kardashian: “Welcome to the Family, Mason!”

 Jean Baptiste Lacroix/

Kim Kardashian may be thrilled to be an aunt, but her mom Kris Jenner is still warming up to her new role as grandma.

"[My] mom is a grandma, and as much as she might say she doesn't like being called one, we know she secretly loves it!!" Kim, 29, blogged two days after sis Kourtney welcomed her first child, son Mason Dash Disick.

"The whole family is so thrilled, excited and blessed to have Mason in our lives and we couldn't have asked for a more perfect gift this Christmas!" Kim went on.

Weighing in at 7 lbs., 6 oz., and measuring 19.5 inches, Mason is the first child for Kourtney, 30, and her on-again boyfriend Scott Disick.

Kourtney and her beau, 26 — who briefly split last year after she accused him of cheating — have been looking forward to being parents ever since announcing they were expecting in August.

"We're home every night looking at baby books and baby magazines," Disick told Us this past fall. "I just want to stay home with her, enjoy her company, look at her stomach and be with her."

The reality star's pregnancy is being chronicled on the fourth season of the family's E! reality series, Keeping Up With the Kardashians, which premiered the night before she gave birth.

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