The Wakeup Call

Rachel is a college professor and usually hires some of her students to help her with spring cleaning around her house. The year she had Lena a cute girl from her class also on the swim team. Lena spends several days helping Rachel and when they are finished, they sit in Rachel's living room and have a glass of wine and watch an old show they both like. Watching the show, the two get into an argument over the female lead and that she is too small to be the tough chick she plays on the screen.
Words go back in forth in good naturedly until Rachel makes it personal and soon the two girls are proving who is the strongest of the two. Though only in her late twenties, Rachel thinks Lena is too small to beat her in a fight. Rachel should have kept her mouth shut, because the younger girl easily lures the cocky professor into a contest that would surely end in humiliation for the loser. But with the adrenalin flowing, Rachel isn't thinking rationally and before she knows it Lena has Rachel flat on her back pinned under her making her say and do the most humiliating things.
When the smoke clears, Lena has left, and Rachel sits on the floor in her front room licking her wounds and vowing to never let that happen again. She would never underestimate someone's abilities by their size. It was her wakeup call and she turned to the Club Antiope, a women's only gym to get her the strength to prevent anyone taking advantage of her again if she didn't want them to. At the Club she builds her strength, and then learns all kinds of self-defense techniques, impressing the owner that offers Rachel a chance to put her humiliation behind her and never submit to anyone ever again.