How do boys reply if they don't believe in constellations?

You can say, "Even if you don't like this sign, you don't care. We can get a general idea of what the constellation is or what you like, and we can get to know it together. " . This is very polite and respectful, and you can continue to communicate with boys. After all, getting along requires everyone to give and take. You can't say you are dead. He doesn't like constellations, so ask him what he likes and say what he likes.