Actor Robert Culp died on Wednesday in Los Angeles after suffering a heart attack outside his home. According to The New York Times, Culp, who had a six-decade career, is best remembered for playing a secret agent masquerading as a tennis bum traveling with his trainer, played by Bill Cosby, in the ‘60s television show I Spy, one of the first interracial pairings on network television. Cosby said that at Culp's suggestion, the two "agreed to make the relationship between the white character, Kelly Robinson, and the black man, Alexander Scott, a beautiful [ital beautiful] relationship so that people could see what it would be like if two cats like that could get along," the Los Angeles Times reports. Each year that the show ran, Cosby beat out Culp to win an Emmy, although there were no hard feelings. After the series ended, Culp starred in Paul Mazursky's swinger film Bob & Carol & Ted & Alice. Hugh Hefner called Culp "one of my best friends," and told the Los Angeles Times that he was "absolutely stunned" by his death.