I have this headcanon that Albus and Scorpius were born almost at the same time or at least only a couple of hours apart so Draco and Harry were stuck together in the waiting room while Ginny and Astoria were giving births. And Harry noticing what a nervous wreck Draco was, took pity on him and awkwardly tried to reassure him because he knew what it was like to wait for the birth of a child for the first time. And when Scorpius and Albus were born, Draco and Harry introduced them to each other. And surprisingly, both dads kept in touch, Harry offering some dad!tips and Draco absorbing all the information like a sponge. And then they organised playdates for their kids and that’s how Scorpius and Albus became bffs literally from the cradle (and James began feeling very protective of both of them).