While on expedition Lumine ended up getting lost and found themselves in the god of Liyue's cave

As Lumine explored the cave she saw Zhongli in his Dragon was curled around his 3 babies ( Xiao , Hu tao and Ganyu ) protecting them as they all slept peacefully

Lumine couldn't help but go and see Zhongli 's cute babies however this caused Lumine to smell like his babies

When Lumine was going to leave the cave she accidently tripped over Zhongli's tail which caused him to wake up , he sniffed Lumine and picked them up and began Grooming them thinking it was one of his babies

When Zhongli finished cleaning Lumine he placed them down in the center of the sleep pile then he curled around his babies again

it seems Zhongli thought Lumine was one of his babies