He can feel that length stiffening under his grip as he continues to tease just the tip of it. "Do I excite you, Lan Zhan?" Because when has he ever been able to resist talking and teasing even during these such activities. He runs his top teeth along the rim before finally wrapping his lips around it so he can suck gently. Everything he does an experiment to see what kind of response Lan wangji has to things. Still fairly new at this kind of act, Wei Wuxian enjoys learning what it takes to truly please the other man. What kind of sensations drive him wild and make him moan for more?