SO Porn Addiction

Hey guys, SO has told me he was addicted to porn before getting with me, and we lead a very transparent, loving relationship. He came to me out of guilt saying he looked at porn again, and stopped to look at pictures I've sent him; but still feels awful. I really understood the slip up, and I didnt mind. But I can't help but feel it's my fault; and that there's something in porn that's better than me. When he got with me he was able to very open with me since I know no bounds in bed. I guess I just want to some encouragement that it's not my fault, and that his behavior is normal.