Warmed by the laughter, small though it is, Wei Wuxian concentrates on kissing him rather than the missive. Forcing his way in might get the job done, but there is so much resistance even against this barely there pressure - it doesn't seem right just yet. He pushes his tongue into Lan Wangji's mouth instead, drawing his forward and sucking on it slowly, waiting for Lan Wangji's breaths to quicken before he pushes forward, sinking his finger in to the first knuckle.