Relationships

Who is the one to blame?

This guy and I have been dating in a long distance relationship for over 7 months. He is in Canada while I am in the United States. When we began getting to know each other for a couple of months he told me he has feelings for me and I was a bit hesitant but I decided to give it a try. In September he traveled to go to a convention in a different state and I saw his picture with this girl and I asked him who it was and it was his cousin but I didn't really believe him. Time came and I traveled to go see him in Canada. We spent some time together and later on I asked for his phone and I went through the messages of him and that girl and that is when I found out that it wasn't actually his cousin, it was his ex girlfriend. My heart dropped cause I thought I trusted him that he wouldn't lie to me such a thing. The messages were like of them greeting each other and her sending him a picture and he complimented it but yet I saw a text of him telling her that he is seeing someone else which is me (because I saw my name). I comforted him about what I saw and he said that: "he didn't know that I was serious with him (though he said he loved me) but until I traveled to come see him" thats when he actually saw I was serious. I asked him why didn't he tell me in the first place that it was his ex and he said that he didn't want to lose me and had feelings for me which is why he didn't want to involve me in the drama and said thats why he left his phone unlocked because he knew I would go through it. . So am I the one to blame that I fell him when he said it was his cousin or is he the one to blame that he probably lied to me and that he could possibly be still dating his ex or have feelings for her?

-No insults please🥺but just me honest with your answers
Who is the one to blame?
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