The juice box

On Sunday, John and Gillian came upstairs to get some juice boxes. Gillian asked John "Can you bring mine downstairs?" John said "No." Gillian said "I can't carry it! It's too heavy." John said "Fine, if I carry it, I get to drink it!" Gillian screamed "No! It's mine!" John said "Well then you gotta carry it." Gillian said "I can't!" John didn't take that excuse, he said "You just gotta be strong!" That worked and she carried the juice box downstairs.