[he's too eager to drag it out for long when he feels him taut and ready under his hands--he licks up and down the length of his cock once before he pushes Lan Wangji's legs further apart and takes him into his mouth. the lack of technique and personal experience is apparent; he takes in as much of him as he can at once, sharp teeth poking at the sensitive skin of his member before he thinks to open wider to avoid that.

but his tongue is as quick and clever as ever, relentlessly exploring every inch of him in an effort to work him back up as hard as he was before]