Diplomacy---skill in managing negotiations, handling people, etc., so that there is little or no ill will; tact:
Ken and I have been married 32 years. Not long ago I had tried a new recipe. A new recipe is not always a success! As Ken was valiantly eating I asked if he liked the new dish? His answer --"well, if you don't like it you don't have to make it again for me!" Now that's diplomacy!