It's another boy for Kourtney!

The reality star, 35, welcomed third child on Sunday -- the same day she gave birth to son Mason five years ago! Happy birthday X 2!!! The "twin" boys also have a sister, Penelope, age 2.

Kourt announced to baby daddy Scott Disick she was expecting during the premiere episode of Kourtney & Khloe Take the Hamptons.

The eldest Kardashian daughter really shared her pregnancy with the world in a recent nude photo shoot for DuJour magazine. Kourtney went head-to-toe nude, with strategically-placed hands enveloping her growing belly.

Kourtney and Scott welcome the newest addition to their growing brood amid recent reports the pair's relationship is on the rocks. Scott's substance abuse has played out on the couple's reality show and Kourtney's been posting "inspirational quotes" on social media ... always a sure sign of trouble.

Still, the couple must be happy today -- a new baby in the family tends to brighten things up!