Her Mother's Daughter - Hotchniss

Seventeen years ago, Emily Prentiss was headed off to Yale when Aaron Hotchner was running her mother's security. The truth is, they had met, while Aaron was off-duty and by chance saw Emily at the bar, both of them blackout drunk when Emily started flirting with him. Emily was leaving for New Haven the next day, they would never see each other again. Perfect for meaningless sex. Nine months later, Emily gave birth to Bridget Prentiss, never thinking to tell Aaron. How would she even go about that?

Bridget had asked about her father growing up, and Emily had told her more as she got older. Finally, when she's sixteen and flat-out asks who her father is, Emily's faced with the decision to tell her first about their one-night stand seventeen years ago, and second to reveal the recent rekindling of their relationship.