From "Homemade"

When they were still in grade school, their mother told them that a good relationship was like a mathematical equation. If you did certain things, and he did certain things, you could be sure to end up with a successful marriage. After that conversation, which was the closest thing they got to the birds and bees, Sarah pulled Teresa aside and told her that their mother was talking about blowjobs and that one day, a boy would pop a pimple in her mouth.