I'm not sure I agree with the parent or not, but there are a few things that I've found incredibly valuable to sustain a successful marriage long term. For example, we have the rule to never go to sleep while angry with each other. Maybe we'll be sitting in separate rooms tired and fuming at 1am, but once heads are cooled off we talk it out and then go to sleep at 2am after both are happy to share a good night kiss. I think this is huge because it prevents anger or frustration to build up and forces it to be resolved at a natural point.