He kept applying the salve as he turned over the information Silvio gave in his mind. He couldn't imagine being so vulnerable for the whole of a week while also being alone. Su-jin spent more time with Tiras the closer his feeding times came. He should eat more frequently, Tiras even encouraged it, but he won't. So he starts to feel weaker and sick. And he starts to spend more time with his partner. Then after, he stayed while the incubus recovered. Usually it was only a matter of days for that, but he couldn't dream of leaving him alone when he's not at full strength. If something ever happened to Tiras, it would be a death sentence for Su-jin.

"That's a long time to be so vulnerable..." As if Silvio wasn't well aware of the fact.