They can't be. Their thoughts are genetic. If one Superhappy attempted to lie to another, the other would read the lie, the intent to lie, the reason to lie, and the truth all in the same breath off the same allele. They don't have separate models of their minds to be deceived as humans do. They share parts of their actual minds. Lying would be literally unthinkable. They have no way to actually generate such a thought, because their thoughts are not abstractions but physical objects to be passed around like Mendelian marbles.