When we deliberately or inadvertently support our children's use of slang, it's as if we tell them: Yes, there is something gross or silly or ugly about that body part. Don't ever call it by its real name.
Schools can and should teach about the nutritional value of meat. That's what schools do. At home I can and should teach about the ethical and moral weight of eating meat. That's what parents do. The same is true for sex.