Kenny Simpson and Krystle Moore bought their first house in 2012 due to the seller’s error. Over the past decade, they’ve grown their real estate portfolio to 47 units worth $19 million. The couple estimated that they net almost $400,000 annually in cash flow from their investments. When Kenny Simpson and Krystle Moore got married in March 2014, they were under a time crunch to take advantage of a tax benefit on the house they had accidentally bought, two years prior, due to a fax error — and were currently in the process of selling. “Everybody thinks it’s the most romantic story ever,” Moore joked to Insider. In the US,…