DH and I have known each other for 3 years, been married for less than 1.
6 months ago, he started declining my advances to have sex and would spend hours every night sitting on the sofa scrolling through his phone and chatting with his friends.
At first I thought it was me, but as far as I know nothing has changed on my end.
So then I thought that he could be having an affair.
I know it’s wrong but I did read through his incoming notifications the other day while he was taking a nap. I didn’t see any indications of an affair but I did catch a glimpse of his group chat.
They were linking usernames on Reddit and Only Fans rating women and making comments like loose, butter face (?), has deepthroat clips and there was even this message where someone said he finally solved it and linked the Instagram and LinkedIn profile of this woman. 
Yesterday night I mentioned it and DH was angry at first storming off to the bedroom. 30 minutes later, he came back and said he didn’t like me looking at his phone (fair enough) but that it was just the boys doing their thing and that there was nothing he could do and that his only contribution (he scrolled through his phone here for me to see) was a comment saying zoom in on her computer screen you can see her work uniform in the reflection??
I feel so uncomfortable with it all. 