Even though he's abandoned her and you.

Alfred: I don't know what to say. Tristan's always been wild. You love him for that.
Susannah: Do I? Yeah, I suppose I do.
Alfred: Susannah, he does love you.
Colonel Ludlow: Alfred! She's to be your brother's wife.
Alfred: Yes, though you might better remind him of that.
Colonel Ludlow: He's not here to defend himself.
Alfred: No, he's not but I see you are here to defend him and what is his. Even though he's abandoned her and you. And I won't even speak of who else he abandoned.
Colonel Ludlow: Damn you, boy. Don't you blame my son for Samuel's death! Samuel chose to be a soldier and soldiers die. Sent to be slaughtered by the men in the government. Parasites like you! Damn and blast you!
[turns to Susannah]
Colonel Ludlow: Damn you too!
Alfred: Shut your mouth! You leave her out of this!
Colonel Ludlow: You get out of my house and off my land.
Alfred: Why? Because I want to serve my country like you did? Or because, like you, I love a woman who doesn't love me? He used her and he deserted her. Your darling Tristan.
Susannah: Alfred, don't, please.
Alfred: I loved her! I love her still. And he stole her from me. If you want to know the truth of it he stole her from Samuel before the war.
Colonel Ludlow: God help me, I'll kill you.

Legends of the Fall (1994) by Edward Zwick