Here's a classic exchange to illustrate the wonderful dynamic between a brother and a sister who are close in age.
I wanted to separately offer Aaron and Jada a big reward if they upped their grades considerably (under the impression that they CAN get better grades but have chosen to NOT YET put in the work and marshal the concentration to do so).
I spoke with Jada first and we decided on a trip to the Holocaust Museum in DC (she's read numerous books on the subject).
I spoke with Aaron second and his request was to come along with us. "I didn't know you were interested in the Holocaust." His immediate reply: "I'm not; I just want to go to bug Jada."
Spoken like a true little brother.