Another way to burn money would to allow the purchase of some big ticket items like a bicycle so she could go on a ride with Ember. A camera or video camera could be used with a photography class or on adventures with Jun. She could also fall for a scam where she damages something and has to make regular weekly payments, but it is something that she won't want to tell anyone about. This option would open the possibility of being encouraged to do lewd things to reduce the debt each week. An example could be the clothing shop guy slipping the expensive swimsuit into her bag and her setting the alarm off; unfortunately, the dress got damaged in the process and she has to pay the full price and if her parents find out, she'll have to spend the summer in her room. She could do some modeling, cleaning, stocking the store, or eventually actual lewd stuff .
Edit:
- The dress thing could also be a way for to work and not get a wage, it just goes to the debt, while keeping her from working the other job and gaining more money.
- The bicycle could lead to an adventure with ember where May can be influenced to be more comfortable with showing her body, like Ember. Maybe taking a break at a secluded lake and going skinny dipping.