Request: A guest offers to bring her seven-layer dip to your party. It doesn’t really go with the Greek theme you have planned.

What you should say: “What a kind offer — thank you. I have already planned the menu, but do you have any dietary restrictions I should know about?” If she’s just asking to be nice and insists on bringing something, suggest a bottle of wine or a loaf of bread.

Why it works: By acknowledging the generosity of the offer, you let that person know she did all she could. Of course, if the person has dietary restrictions that make cooking difficult for you, relent and let her bring a dish she can eat.

Why you shouldn’t feel guilty: The person is most likely offering just to be courteous. By saying no, you give her license to relax and enjoy your hospitality.

How to avoid the situation in the future: When you invite people, ask if there is anything they don’t eat, because you want to make sure your menu works for everyone. Emphasize the word menu, so people know that you have a plan or a theme for the meal (and so they won’t try to upset it).