My husband is on a porn app

Keri
I found an app on my husbands phone called tumblr. I opened it and all he is following is porn sites. He "liked" a ton of women's breasts and pictures of women performing oral sex on men. I consider myself a good looking woman, I keep myself in shape and have nice breast, I please him orally as well so why does he feel the need to do this? This is the third time him and I have had a talk about this. I don't know what to do??!! It worries me he's downloading apps now instead of just looking it up on the Internet.