Well just yesterday Jamie and I finally figured it out... We call each other "Honey". I was calling for Jamie and saying "honey" repeatedly. Caleb then said "ON-EY" What an AHA moment it was! He's been trying to say "Honey" because he hears it from Jamie and me!
The picture below has nothing to do with the story above but I think it's cute. Jamie and I went to Saul's in Berkeley (the only Jewish deli in the Bay Area) and Caleb went crazy for the matzoh ball soup. He couldn't get enough of it.