Most liars don't want you to notice they're lying, this one gets off on it. Like "Yeah, both of us know I'm lying but you can't say or do a damn thing about it can you? Ha ha!". And no one does. Yaniv claims to have a vagina and penis, and to menstruate, and although everyone knows that doesn't happen in humans, no one will say "No you don't. Enough! Stop lying, dickhead!".