"I don't know if I love him or the fact he trusts me. There's a difference." One lasts for however long it's fed. The other... it's only the base of any relationship, be it platonic or not.
Len's question brings a soft laugh. It isn't bitter, empty, or joyous. It just is. "If I did fall in love with him, I wouldn't act on it. First... I'd have to know where the three of us stand. Particularly his thoughts about me."
Barbatos leans in and strokes the prince's hair. "You came first. Your opinions matter. I can't lose you. If we drift apart, it's different. But... I'd rather you drive a blade through my heart than stew in resentment for so long I won't be able to reach you again."
It's not poetic hyperbole. No, the archdemon's words are an echo of experience from eons ago, a lost love he can't let go because he can't figure where they went wrong, he can't let go because part of his heart still belongs to Crocell.
He's still not happy about it ( which might just be the understatement of the year ), but the other man's words and reassurances are enough to placate him, to make the sharp and boiling mess of emotions in his chest fade away. At least for now.
"...I hate how easy I am when it comes to you," Len mutters, but there's no real heat behind the words. He sighs, then, and tips his head into the touch of Barbatos's hand, his own coming up to rest atop it. "Driving a blade through your heart... That's so dramatic. And you know I'd never do that to you."
The blonde falls silent for a long moment. Something conflicted flickers through his eyes, before he seemingly decides on something, and he looks back up at Barbatos.
"...If you ever do think you're...falling in love with him, then...I'd want to meet him. I'd want to know who he is and what he's like."