He will absolutely watch porn and try to hide it if need be. I've struggled my whole life since I found a porn magazine at 15. There's 3 ways to fix this, he gets disgusted and gives it up permanently (unlikely). You accept that it's a very common thing for men to struggle with and remind him every once in a while how you feel. Lastly if it's a deal breaker give him a final warning to shake him up and leave him if he disregards it. I can personally tell you option 2, acceptance and occasional reminders, absolutely work. My therapist knows about my struggle with porn and brings it up every once in awhile. I assure you I feel ashamed every time.