It has been 10 days since my boyfriend received the composite information from his ex-girlfriend. Why?

Your experience is similar. I broke up with him yesterday. We met at my cousin's wedding. It was love at first sight. He is very handsome, 1.8 meters tall, and he is well dressed in all aspects. Comparatively speaking, I feel very inferior and insecure about him, but later he told me a lot about him, his previous affairs, his parents and his love experience, which made me feel that he made a lot of promises to me. He said he wouldn't lie to me, make me think blindly, and be cold-blooded to me. But in a blink of an eye, he got back together with his ex-girlfriend within a few days of going abroad. He stopped contacting me, called him and hung up when he heard my voice. At first, I didn't know what happened. I thought something had happened to him, so I began to think about it. Later he came back and hung a photo of him and her ex-girlfriend on his space. She is also the woman who loves me most. At that moment, I felt my heart stopped beating. Everything in front of me reappears in my mind like a movie. I don't know. What am I these days? Later, he said that his ex-girlfriend was the most sorry woman in his life. He said he didn't lie to me every bit when he was with me, but he didn't expect his ex-girlfriend to get back together with him. Ironically, I always trusted him. So I am.