Pokémon - When your parents abandon you and your siblings for years

its not an edit, this is canon boys and girls

This made me think, Maybe the reason Brock constantly flirts is because he is looking a woman to take home to help raise his 8 siblings as a mother figure.
This may also explain the Jenny and Joy fetish, both are responsible and caring women with large families, so they would be a good fit to help Brock's family.