Tell him you downloaded Reddit and searched his profile just to see what he was interested in and saw the subreddits he was commenting on. Ask him flat out to see his phone as his comments were very concerning. If he won’t give you his phone, then you have a pretty good idea that he is hiding something from you. If he does show you his phone, make sure you search all his apps, not just Reddit. Also, if he has an iPhone take a look at the pics stored/shared on those apps (Settings/iPhone storage/“name of app”/photos)

In the meantime, check your cell phone bills and credit card statements to see if there are any phone numbers that you are unfamiliar with that he is communicating a lot with and charges that seem unusual.

Alternatively, if you aren’t ready to confront him, set up a fake Reddit account (using a fake email address) and send him a direct message. Say you saw a couple of his comments on the affair subreddit and you are intrigued. Tell him you are in the area and are looking for someone to meet up with. If he shows interest ask for a spicy pic. This will let you know if it’s him and how far he is willing to go.

I wish you luck!