She's keeping this billionaire's son a secret...  Down-on-her-luck heiress Piper Mills will do anything to help her baby--even strike a deal with the devil who impregnated her! Due to a car accident, Jaeger Ballantyne has no memory of the passionate night he and Piper shared...or that he's Ty's father. Purchasing Piper's heirloom sapphires is the only thing on his agenda...until seducing the green-eyed temptress takes over.  Piper's falling for the stubborn tycoon, even as she continues to guard her secret. Can a man with no memory of their past find a way to forgive her so they can create a future?  His Ex's Well-Kept Secret is part of The Ballantyne Billionaires series.