<Tr> <Th> Significant other (s) </Th> <Td> Megan Hunt Meredith Grey </Td> </Tr> <P> Nathan Riggs M.D., is a fictional character from the medical drama television series Grey's Anatomy, which airs on the American Broadcasting Company (ABC) in the United States . The character was created by series producer Shonda Rhimes and is portrayed by actor Martin Henderson . He was introduced in the episode "The Me Nobody Knows" as a cardiothoracic surgeon who had worked overseas with April Kepner during her time in Jordan . After bringing a patient to Grey - Sloan Memorial, he begins working there as an attending under Maggie Pierce . At the hospital, he begins a romantic relationship with Meredith Grey, now a widow after the death of Derek Shepherd, until his missing fiancée, Megan Hunt, is found and brought home . Nathan makes his last appearance in the episode "Danger Zone" when he and Megan start their life anew with her son in Los Angeles . </P> <P> Nathan Riggs is introduced in the sixth episode of the show's twelfth season as a new cardio attending at Grey - Sloan Memorial . It is quickly learned that he and Owen Hunt (Kevin McKidd) had been friends, but that their friendship ended acrimoniously . It is later revealed that Nathan and Owen's feud was caused by the disappearance of Owen's sister, Megan . Megan, who had been engaged to Nathan at the time of her abduction, had discovered Nathan's infidelity before running off and ultimately getting kidnapped . Owen has long blamed Riggs for the fate of his sister, who has been presumed dead for 10 years now . However, as time goes on, Nathan and Owen learn to work together and eventually tentatively reinstate their friendship . </P> <P> Towards the end of Season 12, Nathan sleeps with Meredith Grey (Ellen Pompeo) in the back of her car . After the incident, they both agree that it was a one - time thing, as Meredith still has trouble moving on from her late husband, Derek Shepherd (Patrick Dempsey). Meredith also learns that her half - sister, Maggie Pierce (Kelly McCreary), has developed a crush on Nathan, further separating Nathan and Meredith . Still, Nathan continues to pursue Meredith, and although she resists, they eventually begin a relationship after sleeping together again . The two stay together for some time, but just when things are on the verge of getting serious, Megan is found in the Season 13 finale . Meredith sends Nathan off to Megan, insisting that she would have done the same thing had it been Derek . Nathan and Megan initially have trouble resuming their relationship, as she believes that he is still in love with Meredith, but they finally get back together when he brings her son, Farouk, to her from Iraq, proving his loyalty to her . In "Danger Zone", Nathan moves to Los Angeles with Megan and Farouk to start their lives together . </P>

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