Shania Twain pulled back the curtain on her 15-year marriage with Frédéric Thiébaud, revealing that the secret to their relationship is open communication. 8 Shania Twain opened up about the secret to her 15-year marriage with Frédéric Thiébaud. Getty Images8 Twain (seen above with Thiébaud in 2011) admitted she’s the type to want to think issues through alone first. 8 However, Thiébaud (seen above with the country superstar in 2016) likes to talk issues through immediately. 8 Thiébaud and Twain (seen here in 2011) got engaged in December 2010.