She start to press the plug against her tight hole but she can’t seem to make any progress. Taking a deep breath to relax she tries again, this time pressing harder and she yelps a bit, immediately releasing the pressure. She pulls the plug back towards her and he hears her spit, realizing she’s trying to get it wetter. Bringing it back to her arse, she starts to rub it around her sweet little hole. He watches as she rubs harder, occasionally pressing it against her hole but quickly releasing the pressure. Soon she’s rocking back against it, almost like she would be rocking against another person, and he feels like he’s truly going to combust. He slides from the bench to the floor and starts to crawl towards her slowly and as silently as he can. He needs to see this. As he gets close to her he can see her arousal dripping down her legs, but for as wet as she is, she doesn’t have nearly enough on her tightest hole. He wants to cast a lubrication charm for her, but he knows it would give him away. She pushes the plug harder against her hole again and this time it starts to give more easily but he can tell she’s not truly comfortable. She whines as she rocks against her hand and pulls it back, bringing it to her mouth to spit on it again. Of course she doesn’t know about lubrication charms. He’ll have to find some way to put the information in front of her. 