disloyally

Pray, Sir John, by what authority do you act thus disloyally?

He disloyally pleaded that he was much more comfortable that way.

But it was also the end of what Joan had disloyally spoken of to him as her vacation.

He had been disloyally treated by Portugal, he had been dismissed by Genoa.

They were being ruthlessly destroyed by their friends, to whom they had been, so to speak, almost disloyally loyal.