“You know the easiest way to burn the most calories, right, girls?” My best friend’s mom, whom we called Mary Therese, leaned against the doorframe and didn’t wait for an answer. “Sex.” My 9-year-old eyes shot up from the Monopoly game board. “You can burn up to 1500,” she continued. “Really?” I inquired, the whole idea going mostly over my head, but nevertheless, I was intrigued. “You should tell your mother,” Mary Therese nudged. My mother did what other mothers did ― went to Weight Watchers.