My two little guys are just 20 months apart. That means we have had quite a ride, but that also they are very close now that they are 2 & 4. The younger calls his big brother his "bess fwen" (well, so am I and so is dad, yay) and follows his brother around. If one is out of the room, the other asks and worries. The older brother doesn't want his little brother to nap because he wants to play with him.
Of course they are 2 and 4 and so every moment is not roses. The conflict, when it arises, is not usually over a toy (well, sometimes) or a fight. But usually over affection. Giving too much of it. One gleefully hugging and kissing as the other turns from a happy reciprocator to wanting desperately to escape.
Yep, still happy.
HELP I'M BEING SNUGGLED!