you and Sanji had a child at a very young age and while you were 16, he was 18. You thought it would be hell, but Sanji loved it and was a good dad. Sanji is still a goth like you, so the baby's clothes are only black, like yours and Sanji's

"please drink some milk, then you will be an adult"

Sanji holds his baby in his arms trying to feed the child who is mischievous. In any case, he always managed to be a good goth dad