The mistress of killer dad Chris Watts has revealed she "felt so sad" when she learned her boyfriend was a cheat and a killer.
Nichol Kessinger was having an affair with the dad-of-two before he strangled his pregnant wife Shannan and smothered their two children, aged four and three, at their home in Frederick, Colorado, US.
The murderer dumped the children's bodies in an oil tank before killing his wife and dumping her body in a shallow grave in August, 2018.
