I'm going to use my mom's card without her knowing
Do you have a good reason for stealing her card?
I want to buy something even if she gets mad.
It is theft to use your moms card. Your mom could miss bill payments or have to sell something if you steal her money. It is also a crime you could go to jail for fraud.
I'm not going to go to jail for this.
Look she will find out anyways when she gets her bill. You could be in real trouble. Have you considered asking for the money to buy the item or working for it?