Having been rereading Little Secrets as olansamuelle as she reviews, I realized that we encapsulated the twin's relationship perfectly in a few lines. Classic Kala and Jason:
Before Kala could reply, Jason asked, "Daddy, what does Kansas mean?"
"He's been asking everyone that since Metropolis," Lana whispered. "I made the mistake of telling him the name probably came from an old Indian word."
"It means 'Shut up, Jason! Nobody cares'," Kala snapped.
"Kala, be nice to your brother," Clark and Lana said at the same moment.
"Yeah!" Jason added for emphasis.
Repeat as necessary throughout their lives with various topics and sets of parents, mostly Lois and another.
I SO miss my baby twins. XD