After he hit puberty, he got wood, so to speak, so his nose wasn't what grew when he told lies anymore....
"I'm a sociopath with a fetish for my own sociopathness! When I tell lies...it turns me on! See, watch this...the pen, I hold in my hand, is red!"
Doooooooeh!
"Hahah, see, it was blue!"
Doooooooouuuh...
"Awww, damn. Okay, it's red!"
Doooooooeh!
"Ah that's better. C'mere, baby!"