MAAN~What Weaves the Tangled Web

In the play, Much Ado About Nothing, William Shakespeare creates his comedy around irony. In this story, the irony has much to do with misinterpreting of situations which is often induced by lying. My question is is lying ever an ethical thing to do? My immediate answer is no, being raised to believe that lying is wrong and one will be punished for doing so, my impulse is to say the absolute: lying is always wrong. However, in certain instances lying can be justified. As an obvious example, in the Holocaust, was it wrong to say you weren't hiding jews when they were all huddled in your basement? Of course not, you are saving a life and in cases like that, it is wrong not to lie. But in Much Ado About Nothing, there are no life threatening situations, just matters of love and wooing. In such cases, when you are lying about trivial matters such as who likes who, I believe that it is wrong to lie and that tampering with love will only bring complications to a situation that should be straightforward.
In one scene, Don Jon decides to be spiteful and tells Claudio that the Prince is actually wooing Hero for himself and will marry her that very night (2:1:134-140). This was not true, and Claudio soon found out the truth, but to tamper with Claudio's heart even for the few moments that he believed what Don Jon said made him doubt Hero and the Prince, two people whom he loves dearly. To instill such doubt in a person is like poisoning his food, it is often fatal. Had the truth not come out, Don Jon could have done some serious damage.
Another more light-hearted example is when the Prince, Claudio and Leonato fool Benedick into thinking that Beatrice is in love with him (2:2:1-125). It works. Benedick thinks that Beatrice loves him and decides to love her back. The only problem is that Beatrice has no idea of the Prince's plot and is completely baffled when Benedick starts to act like he likes her. Again, not the right thing to do. This further complicates a formerly complicated problem. If in the end, it does end out well and they marry and live happily ever after, that would have happened anyways, without the tampereing of the Prince. Let what is meant to be alone.