I have recently agreed with my student partner that she will move into my flat during the Edinburgh Festival so that she can sublet her room and pay for her half of our holiday together. She maintains that she should pay me for staying in the flat, whereas I argue that this would defeat the purpose of the exercise. How can we effectively resolve this dispute and look forward to our holiday? Should I simply charge her for any increase in my bills, or are there other considerations?
Ben, Edinburgh

Dear Ben,