Here are a few cleaner, more natural rewrites:
Polished storytelling:
He proposed to his mistress with a $150,000 ring right after our divorce… but the next morning, everything fell apart when I arrived with the truth.
Smoother viral style:
Right after our divorce, he proposed to his mistress with a $150,000 ring—until the next morning, when I showed up and everything changed.
Short hook style:
He proposed to his mistress after our divorce… but the next day, I came with the truth.
More grounded tone:
After our divorce, he quickly moved on and made a grand gesture to his new partner—until I returned the next morning with something that changed everything.
If you want, I can also help you turn it into a full story post or make it more subtle and less clickbait-heavy.