same here . . . my hubby was always mistaken as an American and like yours he also answered back . . . “My name is not Joe. I’m not American . . . I’m BRITISH”.
Most of the Filipinos think that if you are Caucasian you are an American.
So far, I haven’t experienced being insulted neither heard any nasty comments regarding me and my hubby.
Just ignore them. . . What matter most is that your both happy and you love each other.