The Valar had warned him and the others.
Master Aulë, specifically, had been particularly adamant: Melkor was not to be trusted, no matter what. He only sought to corrupt and destroy, he’d said.
And yet, Mairon had sneaked away from the halls where he dwelt, concealed behind a dark cloak, keeping his head low as he walked fast to reach the usual meeting spot. He knew it was risky and he dared not think of the consequences should the Valar find out about it, but the desire to seek him out was stronger than the fear of being punished.
There was something about the Dark Vala that he felt incredibly drawn to and he could not explain. He sat by his side, wide-eyed as he spoke of forbidden things.
The sound of heavy yet familiar steps suddenly pulled him away from his own musings and for a brief, fleeting moment, Mairon smiled to himself.
“You are late,” he said, unable to keep a slight annoyance from seeping into his voice as he turned around to face him.