Leon was sifting through the shift and settling in Andrei's emotions, his mental tone. Leon felt that strong mix of happiness - which made him happy, too - and the strong possessive feelings that were mixed into it. Andrei's fangs broke his skin moments later and Leon hissed, the jolt it gave his senses causing a reaction in him that wasn't much different to the reaction he always got when Andrei bit him before. The location of the bite was different, but Leon had been conditioned, he was accustomed to Andrei's fangs, even feeling them pierce his skin to drink moments before he died as a human.
But this time, Leon wasn't a weak human witch fulfilling a deal made on his word that had gradually grown into something much more. He was vampire. The blood that seeped from the bite in his lip tasted like Andrei's blood because it was Andrei's blood that had changed him and given him another life. Leon pulled back, holding steady in his position on top, and he wiped the back of his hand across his lip, looking down at the blood before his eyes shifted to Andrei with a sharp focus.
It was still a learning process between them, knowing when to probe deeper into their connection and when to keep more of a distance or else be roped into the other person's emotions. Leon didn't back off in their bond. He went deeper, embracing that ownership feeling Andrei had tangled in and around his happiness, and he accepted it. Really, Leon knew he had belonged to Andrei long before this, but he had trouble accepting it. Now he was seeing that it had only caused Andrei more doubt and he sent a rush of adoration through their link, despite the sting of the bite.
This wasn't the same as how he felt about Mickey. It was another plane entirely. It was why the idea of choosing between them was utterly impossible. Leon guessed it would always be that way for the ones he fell in love with down the road, through the decades.
The lip was healing and Leon's fangs were out now. He tightened his grip on Andrei's shirt and jerked him up off the ground to partially sit up, sealing their mouths together for more. After all, he may be Andrei's, but Andrei was also his. Leon was protective and possessive of what was his. He wasn't going to risk Andrei retreating again with any doubts about where they stood with one another.