Kylie Jenner‘s showing love to her longtime pal Stassie Karanikolaou … wishing her a happy birthday with a sweet, old school snap.

The reality TV mogul shared several photos in honor of her longtime pal — who turned 27 Sunday … and, on her IG story she went with a pic from their childhood — showing them goofing around in pajamas.

Look at the pic … young Kylie and Stassie had a fun time back in the day — hitting poses and cracking up while the camera caught the candid moment.

While Kylie and Stassie used to do PJs and sleepovers, they’ve obviously embraced night life these days — including last night when the two partied hard … crushing shots and clutching each other tight.

Kylie captioned her post, “for liiiiife. ♾️♾️” … so clearly their friendship’s as strong as ever.

Stassie posted in honor of herself too … though she’s also gettin’ that birthday bag it seems — sharing a post sponsored by Grey Goose.

If you don’t know … the two pals are super tight — Kylie says Stassie’s her oldest friend — and, they’ve both gotten into modeling and influencing over the years. SK boasts more than 10 million followers on IG.

Seems like a hella fun birthday — complete with a trip down memory lane!