Lmao I think mquetoast was very much an understatement based on the way I have heard him described here and in other forums. You are very much right though. Here is a man who took on the role of father of some other man's child as his own and loved her mother with everything he had. Then he took on another woman's children and wanted to be the father for them as well despite how one of them treated him. He loved those girls so much and wanted to be there for them and he was. However, he discovers that the one daughter he has known all her life seems interested in him and knowing what he knows caused conflict in him. Then he finds out that not only one, but both of the other people who always viewed as his daughters are also wanting to love him more than just a father and his mind is in constant turmoil. Many "guys" have been on here talking that he is weak or spinless and he whines but I guarantee that if they were faced with a similar, life changing situation, they too would think long and hard (pun intended) about how to proceed. I knew a guy who had a friend's mother flirt and try to seduce him and I had to constantly hear out his thoughts and conflicted viewing of the situation. He thought he would be betraying his friend if he entertained her. He worried it would ruin things between his friend and his mother. He worried about how the rest of us friend's would view him. This woman was attractive and she had her son at a very early age (she was a minor at the time) and so she was a very young mother comparatively. He didn't realize until months of agony within his own mind that the friend found out and actually had no issues with the situation. Yet he still fought it and hated himself for even considering it. The MC here has a much tougher situation and the roles involved have much higher stakes for him.
Give him the credit for holding out as long as he did lol