Complex sentence: Despite her success, working under a powerful and arrogant chauvinist such as Cedric Gibbons while being married to his brother was not easy and in 1950 Irene Lentz left MGM to open her own fashion house.
Split into simpler sentences: Despite her success, working under a powerful and arrogant chauvinist such as Cedric Gibbons while being married to his brother was not easy. In 1950 Irene Lentz left MGM to open her own fashion house.