Most people will know the classic lip shaped sofa.
But if that is too subtle for you there is this one of a kind pubic sofa that was offered on Etsy.
Just remember never to leave it alone with your penis chair.
Who knows what you might end up with!
On the whole it might be safer just to use real people as furniture.
p.s. This post is too on topic, two of the four pictures have books in them.