Marriage kinda flips the script on what normally keeps folks in check when they're dating. It mixes up what motivates people, sometimes not in the best way. It's tough to tell how much of your partner's behavior is just them trying to impress you before marriage, and how much is actually them. You might be saying 'I do' to someone who's never shown their true colors. Plan accordingly and keep your eyes open. From what I've seen, folks start slipping shortly after the engagement.