Zaul'Nazh never would have treated Leiland the way he deserved. That was one reason Percival was eternally glad that Dark Lord had never moved beyond objectifying comments. If he'd actually pursued Leiland, Percival would have had to kill him. He would not have been able to stand by while Zaul'Nazh abused him. And it would have been abuse. For all that Leiland would have agreed to the relationship because of his misguided feelings, he wouldn't have been emotionally prepared for what he was getting into and would have ended up hurt in more ways than one. That was not something Percival would ever allow.
All the better that Leiland was his now. He pushed down that possessive part of himself, not wanting to let that get out of hand. Leiland likely wouldn't appreciate him thinking that way.
He could tell Leiland was getting a little overwhelmed, but he seemed to be enjoying what was happening. So he kept it up a little longer, still going slowly and easing Leiland into it, before he pulled back. "Are you alright, Leiland?" he asked. "Do you need me to stop?" Because no matter how much he wanted this, he would stop if Leiland asked.