How embarrassing are the other kids that Christian is the one he chose to publicly acknowledge?
Probably less. The obvious reason not to acknowledge them from the start is that they were illegitimate, and for one thing, their lives were less likely than Christian's to be warped by celebrity culture.
Beyond this, Christian probably knew about (at least one of) his half-siblings before these leaks. Even if his dad never intended to exert it, he would have felt the pressure of being "the legitimate one" since he found out. Maybe that wouldn't have affected him at all, but it's a real thing.
