Woody Allen and Soon-Yi Previn: The director had a 12-year relationship with actress Mia Farrow, and cheated on her with her adopted daughter, Soon-Yi Previn.
Gwen Stefani and Blake Shelton: It is rumored that Gwen Stefani started dating the country singer before ending her marriage with Gavin Rossdale in 2016.
Gabrielle Union and Dwyane Wade: NBA star Dwayne Wade was allegedly still married to ex-wife Siohvaughn Funches when he started seeing Union.
Jennifer Lopez and Marc Anthony: It is said that Jennifer Lopez and Marc Anthony started their affair while he was still married to ex-Miss Universe.
Britney Spears and Kevin Federline: The backup dancer was not a free man when he hooked up with Britney Spears.
Kevin Hart and Eniko Parrish: According to Kevin Hart's ex-wife, Torrei Hart, the comedian cheated on her with several women.
Bruce Springsteen and Patti Scialfa:Bruce Springsteen married actress Julianne Philips in 1985 but soon regretted it and realized it was bandmate Patti Scialfa he loved.
Kayte Walsh and Kelsey Grammer: Grammer began seeing Kayte Walsh, a flight attendant he met on a plane, while being famously married to Camille Grammer.
Miranda Lambert and Blake Shelton: The pair reportedly hooked up after performing together at the CMT Music Awards in 2005.
Melanie Griffith and Antonio Banderas: The actors first met on the set of 'Two Much' (1995) and were both married.