There is an expression in Spanish Puño de hierro, mandíbula de cristal whose English translation is iron fist, crystal jaw. But that doesn't make sense to an English person (I suppose) because I used that in a conversation with a native English speaker and she did not understand. English is not my first language so I don't know the correct equivalent.
That expression refers to a person who can insult others (thus "iron fist" which means that he can hit someone easily) but the same person in question can't bear it when someone else insults him (thus "crystal jaw" which can mean that when someone hits them, their jaw easily breaks).
Does such an expression exist in English?