Kiara had previously obtained a couple of pinhole cameras from Aka, with the original intention of installing them in the bathroom to observe how Camden behaved when he was doing his business―don't ask her why she had such a bizarre and morbid curiosity, but she just wanted to know whether Camden, who usually carried himself with a cold and aloof demeanor outside, was actually reading the instructions on the shampoo bottle or contemplating life while staring at the ceiling while squatting in the loo.
Since this guy wasn't like other men who smoked on the pot, nor did he bring books or play PSP there, Kiara's playful mind came up with this prank. She didn't feel any psychological burden at all about playing such a trick on her own husband, as a defiant agent surely had plenty of such equipment on hand.
However, this plan was discovered as soon as it was implemented.
Kiara had thought the locations she placed them were very secret, how Mario Yuno found out about them was a mystery.