Your SIL recently found a young wealthy guy she would like to marry. Once they came to your house and tasted one of your pastries while you weren't there and they loved it

They have a sweet tooth. Your SIL needs to make a good impression in front of her boyfriend's parents so she asked you to bake some pastries again (so she can show off)

You caught onto her plan and didn't make anything so she had to order something which left his parents disappointed

Now she's in front of your house