That Someone is near you for some very important years... you laughed together, you played together, you ate together, you even fought and cried together sometimes. You explored, had adventures, and got in trouble together. And somehow, now that you are all grown up and moved away, you miss them with an ache in your heart that can't be filled by anyone else.
Go ahead, call her!
Text him.
You fill that same spot in his heart because you went through that wondrous and awesome journey of childhood together, elbowing each other the whole way.
Remind him that he is loved, and has been loved,
all the way from the very beginning.