Tell it to the Marines
CATCHPHRASE, ORIGINALLY WITH REFERENCE TO BRITAIN'S ROYAL MARINES
Tell it to the Marines (saying); Tell it to the Marines (catchphrase); Tell It to the Marines
"Tell it to the Marines" is an English-language idiom, originally with reference to Britain's Royal Marines, connoting that the person addressed is not to be believed. The phrase is an anapodoton – the full phrase is "tell it to the marines because the sailors won't believe you", but only the first clause is usually given, standing for the whole.