Have you read the books? They have kids. They butchered the story for the movies though so I could see why non-book readers would think this. Him and Chani stay together in the books. Been a while since I read them but I don’t think she really cared he had to marry the empress, unlike the movie. He never bangs the empress and just stays with chani. Guessing the movie he will just reveal he married her for the title and still lives chani and she’ll be like “deadass? bet” and it will move along.