The context of the following conversation is Casey played a joke on her friend Mandy. Both Casey and Mandy laughed and laughed.:
Casey says I played a joke on Mandy..
The friend responds What was it?.
Casey responds I gave her one of those fake scratchers that show that you've won $10,000.  She got so excited and jumped up and down..
The friend responds And when she found out the truth?.
Casey responds We just laughed and laughed..
The friend responds Lucky for you she's got a good sense of humour..