He rarely was in his corporeal form since they had arrived on Arda, the strife between the Vala and he were best to avoid but on Ainu besides his brother held his attention and it was due to this he came unknown to the maia time and again, reaching into the other and plucking notes of ideas for projects Melkor would only see this one create.
Mairon was sure the other maiar were jealous. He loved the attention, he would freely admit this, but more than that he always felt his projects were better after a visit from Melkor. But of course, the Valar were often busy, and maiar sent off on their tasks. Mairon was not expecting to see his new friend again so soon.
He was in the forges with Curumo, the pair of them arguing over a blueprint, when Melkor entered. Mairon quickly tried to look composed, but he couldn't hide how his fëa brightened even if he didn't smile in front of his brother.
"Lord Melkor! It is an honour, as always."