The two male characters are seen kissing each other on the cheek as they greet each other in a restaurant scene in the animated show.
However, the show's writer, Spencer Rothbell, has confirmed that the gay couple originally kissed on the lips and one of them gave his partner flowers.
The scene was changed in order to get the green light from Cartoon Network, who air the show.
He later added: “It’s such a minor throwaway moment but I guess it’s better than nothing. Maybe one day the main character can be gay and it won’t be a big deal.”
Earlier this year the Disney Channel featured its first ever gay characters when a lesbian couple were introduced in an episode of the sitcom, 'Good Luck Charlie'.
Watch the scene from 'Clarence' above.