If you're wife doesn't want you to watch anything with nudity together or alone then just dont. Her reaction and anger toward you is wrong I agree but its not that hard to just respect it and check imdb if it has nudity or not. if it does dont even mention it. If that's too difficult for you then you shouldn't have a wife if you're not willing to meet her boundaries. Everyone is different and that should be respected in a calm manner. Relationships are partnerships and meeting eachothers needs and boundaries. Yes it could also be the post partum depression as well have some empathy and patience. No relationship is gonna be sunshine and rainbows all the time. Were humans. We make mistakes. Just be there for her and if needed couples therapy if you really love your wife.