Both the reason you think you have to lie, and the lie itself, are both essentially borrowing happiness from the future to have instant gratification/relief now.

From a male perspective, lying sluts are out there and it's up to the man to judge (and investigate if necessary) to find out the truth. At that point, her lie only serves to arm him with "ammunition" to use against her.

I also want to address the popular fallacious argument that these lies are "for his own good": No; it is for her own good, since she are the one who wanted it to work so badly that she lied. If it didn't work out with her, he would've went on to find another woman who didn't have to lie.