Who is Walter Sinclair from Sister, Sister and what is their importance?

Walter Sinclair is Valerie's husband who treats her coldly and indifferently after six years of marriage. He is handsome, broad-shouldered with a football build and was a football player in college who did not make the NFL. Walter is 6 feet tall and weighs 240 pounds. He now sells exotic cars for a living. When Valerie confronts Walter about how he has been treating her, he tells her that he does not even like her and blames her for his failures. He is frightened when Valerie threatens to burn him, but later, he begs Valerie to forgive him because he realizes what a good woman she is.