Your question is difficult to answer. I need many more details. You stated that your ex was not honest about his decision regarding custody of his three children. In what way was he not honest? Did he outright lie to you? It would have been helpful to know what you meant by “not honest.”
Usually, the court determines custody. Did the court determine that the children were best suited to live with their grandparents? He may have very much wanted to be with his children but was not granted custody.
Another possibility, given the situation, is he may have determined that it was in the children’s best interest to live with their grandparents. For example, an analogous situation would be parents who send their children to boarding school. They may not want to be physically separated from their children but determined that the advantages of boarding school outweighed the disadvantages. Most would not characterize parents who sent their children to boarding school as being unloving or uncaring.
On the other hand, maybe he was completely irresponsible with his children. You mentioned that he was not willing to support them financially. Why was that? Was he unable to? Also, I wonder whether he attempts to make contact with them. Is he allowed to have contact with them? If the court awarded the grandparents sole custody, why was that the case? Was there something wrong? The key to determining whether his decision was morally correct (and subsequently determining whether your thinking was logical) lies in examining the circumstances surrounding the custody case.
I want to commend you for your willingness to examine your thoughts and behavior during the relationship. Many people are not open to such a process. It could prevent you from making poor decisions in the future. Unfortunately, given the limited information provided I cannot determine whether your thinking was logical or not. I believe that you are an excellent candidate for therapy. Why? Because you have a specific situation that you want to analyze. A therapist would be able to gather many more details about your relationship and could help you determine whether your thinking was rational and logical.
Here’s a link to a therapist directory. I hope you’re able to eventually figure out the answer to your question. If you would like to write back and provide more details I may be able to give a more specific answer.
Thanks for writing.