Optimus stays quiet and listens to her.
In a way, he knew. During the war and long before it, they had been much closer physically than anything else - always in proximity of Rose, and thus each other, but rarely alone.
He'd known that she was... withdrawn around him, closed off, but it wasn't like he was any more relaxed. Their lives had both existed in service of the Diamond authority, even in their shared act of rebellion.
It really wasn't until much later - after the dust settled and fragments bubbled - that they even started to talk to each other about anything unrelated. Even that was because Rose had ordered them not to.
But now here they were, on a beach, just... relaxing. Existing. It was as nice as it was terrifying.
"I would have to say the same... I accept your apology. I'd like to offer one as well, for closing myself off to everything but our mission."
Even now, it's hard to "turn off" as Steven calls it, just relax. That wasn't how he was built or coded. "If it's any comfort, I often felt envious of you as well. I tried my best to follow orders and meet expectations, but..."
He trails off, looks out to the water. "...but you always seemed to have such clarity in your purpose, such... drive. When I was assigned to Homeworld, it was after... a very big mess. I effectively ruined my own chances of being a proper Prime, and... failed to save a friend of mine, far, far away from here or there. I focused on protecting Rose - even before she was Rose - because I thought I could make up for it by doing better."
A small laugh. "I know it's more complicated than that - believe me, it always is - but you made it look so easy. Combat, teamwork, fusion... I couldn't believe it the first time I saw it. There's this word on Earth for what it was - a miracle. Two lights acting as one. And I... I envied you, and Garnet, and Amethyst and Rose - for being able to reach a sort of unity that I never could, and trying felt... foolish. So it was just easier to focus on my duty and what I could do."
A small pause. He looked back at Pearl.
"And looking at everything you've done now, as a free Gem... I am proud to call you my friend, Pearl."