When a man is dealing with low self-esteem, he'll make mistakes. Big mistakes. I hope you haven't caught him on dating sites or apps. That was another thing.
As the study found, there's a link between self-esteem and regret. In this case, people with low self-esteem don't see their personal sacrifices as being beneficial for their relationship. Actively engaging with one another takes effort, attention, and desire. It says, I want to be with you; I want to have fun with you.