In a video that was posted on YouTube and already has more than two million views, 5-year-old Sadie of Phoenix begs to have her 3-month-old brother stay little.
Sadie sobs while telling the camera that she loves her little bro's "cute little smiles."
"I don't want him to grow up. He's so cute, and I don't wanna die when I'm a 100," Sadie says.
Carson calmly sits there and smiles while his big sis hugs him and kisses his head.
"She's cried about not wanting to get older herself in the past, but this was the first time she was upset about her brother," her father Ryan Miller told TIME in an email. "The funny thing is that this was totally out of the blue -- we have no idea what prompted it."
Just wait until the "terrible twos" come to town Sadie.