I overheard this conversation the other day. I was in my room grading, and my window was open so I could hear my kids playing in the front yard (hubby was out there, too):
Boy: Will you come keep me company while I go to the bathroom?
Girl: I don't want to.
Boy: I've give you two dollars.
Boy: You are the best sister. Of all the sisters, you are the best.
Girl: You are the best brother. I love you.
Boy: I love you, too.
And off they went to the bathroom.