"Shut the front door" is a colloquial expression used to express surprise or disbelief. There are several synonyms to convey the same meaning, with different degrees of profanity: 1. Shut the barn door 2. Holy cow 3. You've got to be kidding me 4. No way 5. Shut the heck up 6. Shut your trap 7. Shut your mouth 8. Shut your pie hole 9. Shut your yap 10. Shut up and sit down. It's important to note that these expressions may be considered rude or disrespectful in some situations, so it's better to use them with caution and only in informal settings.