MAJOR SPOILERS! Why, exactly, did...

... Theo James' character take the baby away from Rooney Mara's character? I know he was bitter because she rejected his advances, but what did he expect would happen if he gave the baby up for adoption? If it was his desire to have her for himself, why did he give up on her so easily? Did he just want to exert control over her and ruin her life for spurning him?