I doubt Barb gave him The Talk. What she wanted was an eternal child who'd never leave her, why would she prepare him for some hussy to snatch him away? Bob might have, he was the one who did the actual parenting.
Regardless of what sex education he had, something clearly went badly wrong. I find it slightly disturbing that Chris can talk quite openly and un-self-consciously about the fact that he fucks plastic women. And in general, his understanding of the subject is about as strong as his understanding of any subject that doesn't relate to Sanic or Pokemans.