Sooo angry!!

My partner asked me to sort something out on his phone, his internet, i had to to it through his settings, I clicked on advanced and it bought up his full history and it's full of porn!!! Yet he swore down on my life and his children's life he hasn't watched porn since being with me because he thinks it's disrespectful, but yet he's only had that number and phone since he's been with me!!! 😷😢 What do I do?!?!