My hero, while embedded with a U.S. military unit in Africa had a one night stand with a nurse and never saw her again.
Years later he fell in love with a woman who turned out to be the one night stand's sister who now has a pair of twins of whom the hero is the father.
All three adults are aware of the situation. The mother wants the father involved with his children and blieves she loves him, the lover wants to get married to the hero. It was suggested they all live together which would obviously raise Morman-like complications.
How can the father raise his kids, marry his lover and what happens to the mother?