Regret
This is true what I'm about to tell you im going to try to get to the point quickly . Me and my wife some years ago met a couple on holiday Andy and Sue and we got on really well ended up good friends and staying in touch . Well we had a big house so they would come and stay with us on occasions and it was good , Unfortunately Sue passed away but we insisted Andy still came and stayed with us it wasn't the same in many ways Andy had changed without Sue . He was lonely frustrated he would say inappropriate things to my wife watch her moving about and kind of letch after her . The first thing he did that I know of I caught him watching my wife sleeping on are bed he was looking up her skirt at her knickers . The last thing to date I feel ashamed of my self my wife does not know anything about this , I caught Andy looking through the glass panel above our bedroom door when we was having fun . Not only did i not say anything I let him keep watching and put on a show for him i don't think he knows I could see him . What happens now?
The two of you should talk to him and invite him to join you both in your playtime. Who knows, maybe that will be the beginning of a wonderful relationship.
I can understand the guy is missing physical touch and sex. It sure has been the root of us males doing some inappropriate and quite frankly some very stupid things.
He fucks your wife and you enjoy watching him stretch her.