This story happened when I was around ten or eleven and my parents were divorced. My dad had a full six weeks with my younger brother and I for the summer and we were really excited to spend time with him. Naturally he still had to work for those whole six weeks but while he had us he also was letting my oldest sister and her roommate/friend stay with him during the summer until school started again and they headed off to college.
This way he had a couple of guaranteed babysitters while he worked very late nights at his job which was over an hour away. My brother and i loved it. Our sister was caring but laid-back and her friend was super nice and easy-going with us two little kids. It was a great summer.
Of course there was that one incident.