A Doll's House
HELMER: "A guilty man like that has to lie and […] has to wear a mask in the presence of those near and dear to him, even before his own wife and children. […] the children--that is the most terrible part of it all, Nora." (1.467)
MRS. LINDE: "they must have a complete understanding between them, which is impossible with all this concealment and falsehood going on." (3.78)
HELMER: "What is this? Someone has been at the lock. […] Here is a broken hairpin. Nora, it is one of yours."
NORA: (quickly) Then it must have been the children--" (3.198-3.201)