Who is Joan's boyfriend's brother?  Answer the above question based on the context below:  Retired gunslinger and former Confederate soldier Steve Sinclair is living as a rancher in a small western community. He collaborates with the main landowner Dennis Deneen, from whom he rents the ranch, to preserve communal stability.  His quiet life is disrupted by the appearance of his emotionally unstable younger brother Tony and Tony's beautiful girlfriend Joan.  Tony has also brought back with him a new beautiful handmade six gun with a filed down trigger. He goes out into the yard to show off his quick draw skills with his other prize possession. The scene ends with Tony finally shooting an image of himself in a pool of water. An old rival of Steve's, gunman Larry Venables, also arrives on the scene looking for Steve. Gun crazy Tony challenges Venables to draw on him.  When a reluctant but belligerent Venables gets distracted Tony kills him. His success goes to his head and he gets drunk, ignoring Joan.  Steve is mad about the shooting and tells his younger brother that Venable was one of the faster gunfighters he ever knew, and that he got lucky. A new problem arises with the arrival of Clay Ellison, a farmer who plans to fence off a strip of land he inherited from his deceased father. The land is currently grazed by cattle and is part of the open range. Ellison has plans to grow wheat on the land and plans to put up barbed wire to keep the cattle off the property.  Tony attempts to drive off Ellison, but Steve intervenes.
A:
Steve Sinclair