So long as general good feeling subsists between two nations, neither will easily take offence at any discourteous act of the other.
I hated to be so discourteous but the only solution was to ignore them.
The discourteous and underhanded treatment of this embassy by Talleyrand and his agents., who attempted to obtain their ends by bribery, threats and duplicity, resulted in the speedy retirement of Marshall and Pinckney.
Among friends we take liberties or say things that would seem discourteous among strangers.
Frame trapping is extremely discourteous, as it prevents the visitor from easily seeing the URL of the site you've linked to.