Call it Fate.

Chongyun gets hired to take care of Xingqiu on his adventures because Xingqiu's dad is worried he might get hurt. So he hires Chongyun to pretend to be his friend and go with him to make sure he's safe, but they eventually become real friends. But when Xingqiu overhears Chongyun and his dad talk, he gets sad because he thinks Chongyun is just faking their friendship, he tries to avoid him and tells him to never talk to him again.

Credit goes to Xingyun fanserver I'm in. Here's the link. https://discord.gg/BhZnzMeRF7