In Episode 2, Nyaruko gives Mahiro a magic charm, initially saying it's an engagement ring. He takes it...and promptly stomps on it.
The eyecatch for episode 2 - Nyarko drinking "Cola of Cthulhu".
Since there are few to no adaptations that make it all the way through the light novels and they're unlikely to be officially translated, would you like to know the ending? Mahiro finally accepts Nyarko's love and marries her, only to have his fears turn out to be justified all along when he loses all his SAN points on their wedding night, screaming such things as "No!", "Help!" ...and "I can't do it anymore!"
Nyarko puts on a pair of glasses in an attempt to be more Meganekko for Mahiro, who isn't impressed. Kuuko, on the other hand?