Hand in Hand

Usually several minutes after fighting with each other, they become friends again.

the Culture Gap

For true Chinese like me, it's not easy to understand some jokes. For example:
Today, my brother lost his first tooth, so I told him the tooth fairy is going to give him money. He now thinks The Rock is going to show up in his room. FML
Who is "the tooth fairy"? Why will he/she give money? And who/what is "the Rock"? What's the connection between them? ...
Thank God, with the help of Wikipedia, finally I got the answers.

Fighting twins

My sons, Sen and Fai, are almost two years old. So, fighting are inevitable.