Do you tell the truth which would be very unkind. "I don't like you. I don't want to spend any time with you"? That would be harsh . I guess if you say " I have other plans but thank you for thinking of me" that's best. What other plans? Not spending any time with him or her or them. Or do you accept, dread going but go anyway because you don't know how to say "no thank you"? If you do or did well didja ever have a really good time and were glad you went?
