You’re not married, so you don’t need to worry about in-laws, right? Wrong. What you know and understand about in-laws when you’re single, dating and engaged can make a huge difference in your future marriage. Deb DeArmond has studied and surveyed in-laws (and is one herself), and offers both some horror stories and frank advice on choosing good in-laws, being a good in-law (son or daughter) and showing grace to the family you might join someday.