"It couldn't hurt, aye? Especially if you are worried that something could happen to both of us." Because from what the angel's told him, if his vow did end up breaking it would result in consequences for both of them.

He's glad, though, to hear that Beelzebub's at least thinking about asking. Even though it seems unlikely to him that the angel might affect him if it hasn't happened already, he doesn't think it's a bad idea to be prepared.

"Who are you thinking of asking?" A beat, and then he guesses, "Lucifer?"