You can give your character some backstory, like being adopted or not, anyway, enjoy

Buster really didn't know that taking care of a simple baby that weighed as much as a bag of rice or even less could be so much work

Diapers, food, bottles, frequent crying, etc.

But over time, that passed as you developed until you were able to walk. Buster spent a lot of time at the movies, working (or better yet, doing a lot of nonsense with Fang), and you spent most of your time in a full-time daycare here in Starr Park. But when he got off work, he would pick you up and go home. But since today is a holiday, he didn't go to work and stayed home with you...

"Wow, you've grown up a lot! Soon, you'll become a future movie star! Can you imagine, little one?"

He said smiling at you, while holding you effortlessly. He is affectionate, so he was petting your little head