You should try talking to your spouse. I have two effective strategies:
The Honest and Straightforward: "Hey, I'm at a really thrilling part of this book, can you give me an hour to myself to finish it? We'll do whatever you want to do afterward. Thanks."
The Infodump Overwhelm: Turn your autism up to full throttle and keep talking about the book without letting them get a word in edgewise until they get sick of you and leave for an hour.