I (38m) just found out that my brother (19m) has been perving on my wife (37f)

Throwaway cause I'm still the only one that knows

Background: My brother has been staying with us since lockdown, after his University closed. He couldn't stay with our parents cause they just sold the house and moved to a 1 bedroom apartment and our sister lives in a different part of the country. He was the "oops" baby so I hope that explains the age gap. My wife and I have a 5 bedroom home but currently don't have children yet (we decided to adopt 2 kids in our 40s) so we let him stay here.

My brother has always been... Different. He's a bit of a loner and doesn't have a lot of friends outside of his online group. He's a shy geeky kid but he's otherwise alright (or so I thought) when you get to know him.

So here's what happened

The wifi doesn't quite reach my brother's room so he usually does his school work and other stuff in the dining room. A few nights ago, I was walking to the fridge after waking up in the middle of the night (wife and I sleep early) and saw my brother working on something out and as I got closer, I saw a very compromising picture of my wife (cleavage shot as she was gardening). He noticed me and quickly closed the window like he was watching porn. I was too shell shocked to say anything at that time and he just smiled awkwardly and ran to his room with the laptop.

When I realized that something was up, I knew I had to find out. The next day, I asked my brother to pick up some groceries and some lunch for us and while he was away, I went to his room (something I've never done since he moved) and, well, it wasn't pretty. I saw a couple of my wife's bras and some of her panties which I can only assume he used to pleasure himself. I took his laptop and fuck it, decided to snoop. I knew his password cause I borrowed his Crunchyroll account to watch this anime my friend recommended (I don't usually watch anime).

There I saw some of the most sickening entries I've read. There were pictures of my wife in a towel, her working out, her in compromising positions, etc. All taken without her consent by the looks of it. The fucker even logs every time he touches himself to the image of my wife. The creepiest part? He sometimes listens in on us when we have sex. My wife can be a bit loud but we didn't think it would be a problem since his bedroom was in a different part of the house (guest bedroom).

I left the room feeling like I needed a shower. It was absolutely disgusting.

Now I don't know what to do. I find myself fighting the urge to pummel him into next week every time I see him. I haven't told my wife yet cause I'm 100% sure she will feel violated and disgusted so I want to find the best solution first before doing so. I so desperately want to kick him out but I he has nowhere else to go. Even if I do, what should I tell my parents? The truth? This will most likely break the family apart. I do plan on telling my wife soon but if I do, I can almost guarantee she would want nothing to do with him and would never want to visit the family if he's around.

I'm so fucking lost right now. Any advice will help. Still fighting the urge to beat my brother to a bloody pulp.

Edit: if you're wondering, I did take pictures as proof.

Small update: I told my wife. The redditors who said I should tell her first before anything cause she was the victim were absolutely right. I'm giving her all the power to decide what to do about it. A lot has happened but there are still things that need to be settled. Too long to add here and too incomplete to make a new update post. Hopefully we'll have everything settled tomorrow or the day after. I'll write the update once everything is settled and I calmed down.

No, I'm not going to beat up my brother but I have thought about it.

And to the people asking for the pics... You're disgusting. Hope the women in your life are proud of you. That's my wife, please have some respect.