Mrs. Buffalo Bill?

After he was turned down by women and friends for dinner, Bill sneaks into Jo-Jo's house by a window out of desperation, surprising her after a disastrous date with Nick. After seven months of flirting with and dating her, Bill proposes marriage to Jo-Jo and sleeps with her, but then he has second thoughts. To his relief, Jo-Jo refuses to marry him, only to have her change her mind to please him. Becoming indecisive, Jo-Jo says "tails" for refusal and flips a coin that shows "tails", setting both free from marriage.