Boyfriend spying on neighbour and masturbating. AITAH.

My boyfriend admitted last night that his neighbour frequently leaves her curtains open while she undresses. He told me he gets so turned on by this that he masturbates when watching her naked and has been doing so for several years now. In addition to this, I found on our computer’s browsing history voyeur websites which have videos of unsuspecting woman filmed in their own homes.

I told him this is wrong and that she likely has no clue that he is spying and in response he blew up at me and deflected massively. AITAH for judging him?

Edit: made new account so I could post anonymously

Edit: before you cry fake, maybe consider that this is a real person struggling with something who is reaching out. I’m not interested in Karma and will be deleting this account once I’ve figured this whole thing out. I’m too old for making fake posts.

Now I think about it, people saying it’s fake shows me how unusual his behaviour actually is.

Update: thank you for all your opinions and insights. I’m definitely going to leave him now, as his behaviour may not be illegal in my state but it’s creepy.