Despite his earlier comment on not having a cameo in the film due to the fact "[He] didn't do that one." during his panel at C2E2, a fan asked Stan Lee if he will have a cameo in Guardians of the Galaxy.
He confirmed he will, but said he had no idea what was going on during the scene or why it was happening, but is filmed with a beautiful woman.
He joked fans will have to explain it to him after they see the scene.