Coming up with a plan for my sister at air conditioner appointment time

I had to find a nice way to tell my sister that I didn’t want her at the house when the men from Air Conditioning Adelaide were due to come over. I knew exactly how she was going to act, and although it was her house too - I didn’t want her there. I had booked an appointment to have the air conditioners in our home serviced and cleaned. I liked to be prepared, and although it was the middle of winter, I thought it was a great time to have it done. Yemi, my sister, had told me that she was happy to pay for half of the service cost, which was great. Once I continued to talk about the men from Air Conditioning Repairs Adelaide and tell Yemi about the appointment, she started making some inappropriate comments. She was more concerned about getting one of the guys from Air Conditioning Service Adelaide to take her out on a date, than having the air conditioners serviced. I became angry with Yemi almost instantly. I knew that she was going to embarrass me if she was here when the technician’s turned up. I had to think about this, there was a few ways I could go about it. The first thing I thought, was to tell my sister that the technicians were coming at a different time. Then I thought that instead of lying to her, I could just tell her that she wasn’t allowed to be her usual flirty self. There were problems with both of my plans so I needed to think about it a little more. I also didn’t want to hurt my sister’s feelings by telling her she wasn’t allowed to be her usual, flirty and embarrassing self.