Hey folks - I've been messing around with this in game, and although it has been difficult at times I've been able to complete it. I'm going to have a chat with our designers about re-thinking if it's balanced properly; the intent certainly isn't for people to need to nearly destroy their relationship to complete this aspiration.
Try this...
For the Sim that's trying to complete the aspiration, pick a Sim other than your spouse and do Mean socials on them until your own Sim turns angry from the conversation. Now, have your Sim do a single Mean social on their spouse, and then immediately apologize afterwards. The aspiration should complete at that point. Your spouse shouldn't have to do anything, and it shouldn't matter what emotion they're currently in. Hope that helps!