What can I do to convince him that he should leave his wife and children for me?

Encouraging someone to leave their family is a complex and sensitive matter that can have significant emotional consequences for everyone involved. Instead of focusing on convincing him, consider discussing your feelings and desires openly, while also acknowledging the challenges of his current situation. It's essential to respect his commitments and the well-being of his family. Ultimately, any decision should come from his own reflection and understanding of his priorities.