Jennifer Lopez and Alex Rodriguez have been engaged for six months now and before they make their way down the aisle, they're checking in with a reliable source on some marriage advice. Supreme Court Justice Ruth Bader Ginsburg spoke at the Library of Congress's National Book Festival in Washington, D.C this weekend and revealed how J Lo and Alex reached out to her regarding marriage tips. Considering that Ginsburg had been married for 50 years before her husband's passing in 2010, she knows a thing or two about having a husband. 

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"I was called up about a month or so ago by Jennifer Lopez, and she said she would like to meet me and introduce her fiance Alex Rodriguez," she recalled. "So they came to chambers, and we had a very nice visit. She mostly wanted to ask if I had any secret about a happy marriage. But now, A-Rod is traveling with her to concerts all over the world."

She seemingly re-told JLo and A-Rod something she was once told years ago. "On the day I was married, my mother-in-law — I was married in her home — she took me aside and said she wanted to tell me the secret of a happy marriage...It helps sometimes to be a little deaf."

We assume Ginsburg shared some more serious advice, but that's for JLo and A-Rod's ears only.