"You have no idea," Seto says, and it's not insulting so much as it expresses a grave pity for Yuugi. Seto was the provider, the one who made incredible sacrifice to give to his brother what he could never have. He cared for Mokuba...but lacked the emotional acuity and self-preservation to be the best brother that he could be.

That, and years prior, losing sight of his goals and becoming the monster he'd fought to protect Mokuba from.

Mokuba, on the other hand...sure, he could be a little shit often enough, but he had remained mostly unspoiled by their home life. That was by design. And...well, he was the more emotionally attuned of the two Kaiba brothers.

He was the one who could see through others, right to the truth of their natures, in a way Seto never could.

Maybe Mokuba would be able to understand why it was that Yuugi considered Seto to be a better confidante for pain, because Seto himself isn't sure whether to take offense or not.

"So it's something to be hidden, something to be ashamed of?" Kaiba asks plainly, looking Yuugi in the eye as he asks.

Is it shameful to feel pain, Yuugi? Is this the shame I'm relegated to for the rest of my life?