"It's this thing our family does [...] kind of like a scavenger hunt. We visit a bunch of places and have fun." (5.54)
This is the start of Amy and Dan's white lies that get them ahead in the competition. They fail to tell Nellie the whole story, that the "scavenger hunt" is actually a cutthroat, life-or-death competition.
Grace had always insisted she had no photographs of [their parents], though Dan never understood why. (6.87)
Even good old kind-hearted Grace has lied to Amy and Dan before. It's hard to believe she never had any photos of her own daughter. Even if she has her reasons, could they be good enough to keep photographs we're sure she has away from her grandkids?
Back in the Cold War, [Irina Spasky] and her KGB colleagues used poison-injecting umbrellas, or spray painted toxins on toilet seats. Those were the good old days. (7.2)
Is Irina Russian for "liar"? She's painted as such a dishonest communist, she might as well have stepped out of a time warp from the days of the Soviet Union.
"You're concerned for our safety? That's very cute, Dan, but the thing is [...] I DON'T BELIEVE YOU." (8.151)
The Starlings are pretty deceitful themselves, so they believe that others are deceitful to them, including Dan. Unfortunately for them, Dan is not being deceitful toward them, and their misinterpretation leads them to getting blow up.
"I don't know if we'll have enough [money] to get back. If Nellie finds out--" (9.105)
While this isn't exactly a lie, Amy and Dan are selectively keeping information from Nellie in order to keep her around, which benefits them in the game. Seems like they've learned quite a bit from their duplicitous relatives, whether they realize it or not.
[Alistair] had been spying on Grace for years, learning her purpose. (10.38)
If Alistair really knew Grace's purpose, we think he wouldn't be so terrible at figuring out the clues. This sounds like another lie to us, to try to get people to think he knows more than he actually does.
"Don't you get it? That's just a cover. [...] Paris is a Lucian stronghold." (12.28)
The Maze of Bones teaches us that Paris was built on top of two things: intricate catacombs and dirty lies. The Cahills' influence is everywhere.
"Tell them you can figure out the book!" (14.94)
Are there such things as good lies? Amy has a choice here: lie to the Holts in order to get out of the hole, or be buried alive by cement mixers. She chooses to lie. We think that was the right choice.
"I was trying to tell you. [Ian] didn't give me anything! I'm not poisoned." (18.91)
Amy finds out that the antidote she exchanged her clue for is worthless. The Kabras totally pulled the wool over her eyes. Well, they pulled the fine, imported cashmere over her eyes. At this point, pretty much every family member has lied to her. Will she ever be able to trust anyone again?