This big brother can't contain his excitement for his little sister's pre-K graduation

(CNN)Graduations are emotional. Especially when it's your little sister.

A Connecticut mom captured the moment her 8-year-old son Derek congratulated her 5-year-old daughter Charlee after her Pre-K graduation and the image is making the rounds on social media.
Aundrea and Matthew Smith posted the photo on Instagram saying their son walked up to their daughter to give her a hug ... but that wasn't all. He had some words of encouragement to add.
"I'm just so proud of you," he said.
    That's when Charlee started crying and quick to follow were mom and dad.
    When dad asked her why she was crying she said, "I'm just so happy." We are so blessed."
    Aundrea Smith said the two siblings have a great relationship.
    "They definitely have their moments when they get on each other's nerves," she said. "But he (Derek) works really hard to be a good big brother ... always looking out for her."
    The post is filled with comments and tags from others after the post asked for people to "tag someone who is a blessing in your life."
      Aundrea Smith said after seeing how much attention the post has received she's happy that her family could bring joy to others.
      "We were not expecting this," she said. "It's a blessing."