The reaction of a young boy seeing his new baby sister is going viral.
Justyce Shavue' posted the video on Twitter, which has already been liked 337,000 times and retweeted over 81,000 times.
"Y'all , my bestfriend had her baby today. & this was her sons reaction to meeting his sister for the FIRST TIME. My heart 💜."
The young boy's eyes lit up and exclaimed "My sissy!" upon seeing his new baby sister for the first time.
He got to hold her and give her kisses.
We can already tell he is going to be a great big brother.
Watch the video in the player above.