French sister

My sister asked if she could go with me to the south of France to spend her vacancies, I told her that she could go if she paid a third of the apartment's rent because I was going with a friend and if wanted to go she had to pay too. The problem was that she didn't had enough money to pay her share so we agreed she would pay half with money and the other half with her services. We spent a great time! We fucked our brains out with my sister and others.