We always like to think that the person who we are in love with is perfectly trustworthy and will never lie to us, but that is not always the case. Many people find that out when they catch their significant other cheating, filing for divorce, or expecting a child. It is often thought though that men are the main perpetrator of these actions and women are typically the victims. In fact, women are just as capable and willing to perpetrate acts of cruelty and deceit upon men, and in some cases more willing and better able to.
Henrik Ibsen's 1879 A Doll's House is a perfect example of this, as is the movie Dirty Rotten Scoundrels, directed in 1988 by Frank Oz. In A Doll's House, Nora Helmer (played by Jane Fonda in Joseph Losey's 1973 interpretation and Claire Bloom in Patrick Garland's 1973 version) forges her father's signature to borrow money in his name. When she does this, she tells her husband, Torvald Helmer (depicted by David Warner in Losey's version and Anthony Hopkins in Garland's adaptation), that the money is a gift from their father as he was lying on his deathbed.
As Sir Walter Scott's saying goes, though, "Oh what a tangled web we weave when first we practice to deceive." After some time it is discovered that she had forged the signature when it is revealed that the papers had been signed and dated after her father's death. She does everything in her power to keep her husband from finding out the truth, but in the end he does, and after his outburst she leaves him.
In the movie Dirty Rotten Scoundrels, there is a character, "The Jackal," similar to Nora, except for one key difference; "The Jackal" has been doing this for a while and is making a living of it. It is an interesting question to pose that maybe eventually Nora will turn to living off men and taking their money from them.
The same basic principle applies to both women, though; they deceive to get what they want. Nora, however, does so for her husband's health as she uses the money to pay for a therapeutic trip. "The Jackal," in Dirty Rotten Scoundrels, on the other hand, uses deception to advance her own place in life. That may be the only thing that truly separates them, though. "The Jackal's" apparent lack of conscience will eventually lead to her downfall, but Nora's selfless action is possibly her only saving grace.
This certainly gives a clear view of the reason most people do not exactly trust their loved ones any more. No matter how much the latter love the former, the latter's thoughts are not out in the open for anyone.