I know I am WRONG but…

I F24 asked my ex if he was seeing anyone during our break up since we were discussing rekindling things and making it work. I asked him M28 if we he was seeing anyone else. He said no plain no! I looked on his phone which he has never given me access to because he said it’s private. But I had a feeling and he indeed was seeing another woman during our break up and said he loved her hours ago. Why would he lie? I know I should not have broken that boundary he said and I am hurt now because he lied. Is he wrong for lying ? Or am I just the B who went through a phone without permission and this is what I get?