King Cairo is one amazing big brother!

In a ridiculously cute video posted to Instagram, the four-year-old gives his newborn sibling Dream Kardashian a kiss on the cheek as she sleeps in her crib.

MUST SEE: Blac Chyna Breastfeeds Dream Kardashian in Up Close and Personal Photo — See the Intimate Pic!

The tot can be heard whispering before gently reaching down to smooch the infant, who was born on Nov. 10.

Dream is the first child for Blac Chyna and fiancé Rob Kardashian. King's dad is rapper Tyga (aka Kylie Jenner's longtime boyfriend).

The 28-year-old mother-of-two showed off her impressive weight loss just nine days after giving birth, revealing that she's shed 15 pounds so far.

Her remarkably flat stomach caused some fans to question whether the model had undergone a tummy tuck, which she promptly denied. "The only reason it got that flat, you guys, is from breastfeeding and breast pumping and from my body already being small before my pregnancy," the reality star wrote.

Scroll through the gallery below to see more pics of baby girl Dream!