Meet the Bickersons.

Levi and Sullivan are good friends. Levi is often the odd brother out when Zane and Titus team up. But he always has his baby sister to fall back on. In fact, they play together pretty much every day when Levi finishes his school work. Sometimes she plays Lego Ninjago with him; sometimes he plays dress-up with her. Fortunately, he has never dressed himself up, but he is willing to help her put all of her accessories on. Looking at the happy couple, it's hard to imagine that they bicker a lot, but they DO. They also love each other a lot. :)