[air one's dirty linen in public] or [wash one's dirty linen […]

American Idiomatic Expressions This online dictionary of idioms and phrases […]

[catch (someone) dead] {v. phr.}, {informal} To see or hear (someone) […]

[catch with one's pants down] {v. phr.}, {slang} To surprise someone […]

[lose one's tongue] {v. phr.}, {informal} To be so embarrassed or […]