When do you lie? What do you regularly lie about?
This could be as deep or as surface-y as you’d like for it to be. Think about something you are consistently less than truthful about and dig into it. Maybe you lie to your spouse about money because you saw your parents regularly getting into terrifying fights about money growing up so you lie to feel safe. Or, maybe you lie to your boss because they have unreasonable expectations and lying is the only way to keep boundaries with them, maybe you’re in the closet, maybe you secretly got a nose job and insist you didn’t, or, maybe you forbid your kids from drinking sodas but you sneak one every time you leave the house. Whatever it is, sit with it, think about why you’re motivated to lie in the first place, decide how you benefit from lying (otherwise you wouldn’t do it), and then write it out.
Remember: You can destroy the page after you write if you need to. But, the act of writing, even with the intention to destroy the writing, still matters and is still worth doing. But, maybe you’ll write it and like what you write and want to do something with it. Only you can decide that.