Give me some advice

I posted yesterday about my bf telling his friend he can let go of his first crush. Idk why it went up as anon, I must’ve accidentally pressed it.

So just a recap i woke up yesterday to a message from my friend of a screenshot of my boyfriends friends Instagram messages between him and my boyfriend. My boyfriend sent this girl’s profile (that he told me about at the beginning of the relationship) that he couldn’t let go of that first crush. He liked her In middle school, need I remind you we are seniors now and we’ve been dating for a year and 4 months. they never became a thing because she friend zoned him. He strictly told me when he first mentioned her that he didn’t feel anything toward her anymore. So when I woke up to that message, I got mad. Before I actually told him about the message, I gave him a chance to be truthful and tell me what he said to his friend. His response was “I just told him she was a friend in 7th grade” which is a complete lie. So when I told him, he was pretty much denying that he had some other girl on his mind, etc. THEN, when I told him I received that screenshot, he got extremely quiet and said “oh” under his breath. Which yes he just lied to me to my face. He eventually admitted that he has had this crush for a long time but he doesn’t even talk to her or what not. He follows all of her social media accounts and likes a majority of her stuff which he didn’t even do to me lmao. and he said he suppresses the feelings because he “really loves me and wants to be with me.” I don’t like the fact that he likes another girl while dating me, and especially waits this long to say something like that. So I made him block her on everything, which is something I hate and never do, but I couldn’t pass up this time. I’m kinda torn between ending it or not. He is begging me to stay or whatever but idk. The feeling is 50/50. I put in a lot of effort with this guy and I don’t wanna see it crash and burn because of something like this but then again he just lied to me.

Y’all please help me. And be mature about this please.