The Donation Oscillation

S12 E15: Penny tries to seduce an abstaining Leonard to ruin his “donation” for her ex-boyfriend, Zack, and his wife, Marissa (recurring guest star LINDSEY KRAFT). Meanwhile, Howard, Bernadette, Raj and Anu turn Raj’s canceled bachelor party into a “couple’s trip” aboard the “Vomit Comet.” Keith Carradine returns as Penny’s father, Wyatt.