What is an example of situational irony in Soldier's Home?

When you are in a situation and your best friend really needs to tell the truth, when they have never lied in their entire life, ever! But then, they tell a lie. like in THE CRUCIBLE, John Proctor admits he is a lecher, but Elizabeth Proctor never lies... however her knowledge of John admitting is not there. Elizabeth denies that John is a lecher, and bad things are to come.