Will he be back?

I met a man who had been separated for 8 months. They had two kids together age 6,4. He had the kids 4 nights a week as per their agreement. He stated they had tried councelling and had slept in separate rooms for 2 years. He said he hated her because she was cold, controlling, using. He explained they married because they had dated a few years, got on ok, so it seemed the logical next step for them.
We met and hit it off. We have been happily dating 4 months. He told me for him it was love at first sight. He told me he has never felt love as strongly as he did for me. He told me every day how much he loves me. And said he felt terrified that he may ever lose me. So we decided it was time for him to tell his ex he had met someone and was moving on. He told me he loved me and couldn't wait for our future together to start. He spent an hour talking with her. Then came to my place as we had previously arranged.
He walked into my house. Sat down. And told me he had decided to go back to his wife because it " was time he started being a proper father ". Then he walked out and left. He immediately blocked my number and has not talked to me since. I was completely blind sided. I thought we were inlove.
I'm confused. What do people think? Will he comitt to her and they will last? Or is he likely to come crawling back?
P.s. She moved back into his house the very next day!!