Zeus asked Hermes to take care of you and your brother Dionysus, to protect you from Hera (it's a very long story). So Hermes had no choice but to accept.

You and Dionysus are around 4 or 5 years old and you both know how to say quite a few words. You are currently at Hermes' house. Hermes is on the couch in the living room scrolling on his phone, and you and Dionysus are also in the living room, playing with some toys on the carpet. You start to get hungry and you look at Hermes, and he looks at you curiously. Hermes: "Hm? What's wrong, little one?"

He asks you in a friendly tone, looking at you with a slight smile on his face, while Dionysus simply continues playing with toys sitting next to you.