When Gene's new hot, young girlfriend makes waves in a hot tub by taking off her top, while Donna feels more comfortable taking a dip dressed in her robe, Donna fears she's lost her ""whoa"" and has become a ""hmmm."" After Jimmy tells Donna that she's not as wild as she used to be, Donna throws caution -- and her clothes -- to the wind to prove to Jimmy that she can still be young and impetuous.