prude

One who is excessively concerned with being or appearing to be proper, modest, or righteous.

A woman who affects rigid correctness in conduct and thought; one who exhibits extreme propriety or coyness in behavior: occasionally applied also to a man.

A woman of affected modesty, reserve, or coyness; one who is overscrupulous or sensitive; one who affects extraordinary prudence in conduct and speech.

A person who is or tries to be excessively proper, especially one who is easily offended by matters of a sexual nature.

a person excessively concerned about propriety and decorum