I would choose Henrik Ibsen's 1879 play A Doll's House, filmed twice in 1973 by Joseph Losey and Patrick Garland, respectively, to make a presentation to an audience on Sir Walter Scott's famous statement, "Oh what a tangled web we weave,/When first we practice to deceive!" I believe A Doll's House would be a good work to discuss because it is full of lies and deceit within a marriage.
In the play and films, Nora (Jane Fonda/Claire Bloom) is a housewife who tends to the house and children. To her husband, Torvald (David Warner/Anthony Hopkins), she is thought of as nothing but a doll to play with. Torvald has pet names for Nora, and he expects her to prance around the house as if she were his little pet.
There is a lot more to Nora than one sees at the beginning of the play. Nora is a strong woman and very smart, despite how she acts. Nora begins to weave her web when she secretly takes out a loan, forging her late father's signature to help Torvald get away and recover from a terrible illness. Nora can never tell Torvald about the loan because, as a lawyer, a such a debt could ruin his reputation; so she keeps the secret to herself. But everyone knows one cannot keep a secret quiet. There is always someone else who knows what one has done.
In Nora's case, Krogstad (Edward Fox/Denholm Elliott), the man from whom she borrows the money, comes back to taunt her with the idea of revealing her actions to Torvald. Nora tries to keep the loan a secret not let Torvald find out because of this man. Nora had been able to pay on the loan behind Torvald's back.
Nora not only lies to Torvald by not telling him; she also forges her father's name in order to take out the loan. This could get Nora in a lot of trouble as well. The deception begins when Krogstad threatens to tell Nora's secret. Nora acts as if she needs help with dances and things to keep Torvald away from the mailbox. She also sends her friend Christine (Delphine Seyrig/Anna Massey) to the man's house, making him think she is in love with him again and trying to stop him from telling Torvald. So not only does Nora deceive Torvald; she also sends her friend to manipulate the man she once had jilted.
In the end, Krogstad has already sent the revelatory letter to Torvald before Christine arrives. When Nora sees the letter in the mailbox, she does everything she can to keep Torvald from collecting the mail, but eventually he sees the letter. When he reads it, he lashes out in anger, letting Nora know how awful she is. Torvald then sees that the man is not going to do anything and forgives Nora, but Nora does not want forgiveness--she is ready to make a new life for herself. Her lies and deceptions having consumed her; she needs to make a new life free from deception and serving as Torvald's pet. In Nora's case, the web she weaves causes her to realize life without deceit is a much better way to go.