Sissy’s third husband is really named Steve, but we don’t learn that until very close to the end of the novel. As a general rule Sissy has him wrapped around her finger, but he puts his foot down about not wanting to adopt another man’s child. He tells Sissy about a young girl who is pregnant with a married man’s baby though, which raises questions about what he thinks Sissy will do with this information. Does he know her well enough to know that she will find this young girl and adopt the baby? And if so, does this mean that he is the father of this child given how adamant he is about not raising another man's baby?
Steve's character goes through a big change when Sissy’s first husband dies in a fire. Because he never remarried after Sissy, and they did not get formally divorced, Sissy is listed as his wife. Her picture is even in the newspaper as his widow. Steve orders Sissy to legally divorce her other living ex-husband. He wants them to get remarried in the church, and he orders everyone to call him by his real name, Steve.
By reclaiming his identity and asserting his wants and needs, Steve has become a respectable man. Finally, a Rommely sister has a strong man in her life, and Sissy is very much in love with him at this point.