Watari Wataru. Pink time of my school life a fraud (№ 383424)

Invited - give up. Action single in the name of preserving the balance and the instinct of avoidance. I mean, if you answer "okay, I'll go", and it turns out that it was only formal politeness on their part, will be very awkward. Just like at a party in high school, when they strained laugh and say "Oh, you coming too?.." Courtesy need to respond with courtesy, it's called etiquette.