I opened a joint credit card with a former boyfriend years ago. I was entirely debt-free when I met him, and after 3 years, I accumulated around $30,000 debt in credit cards. I had him as an authorized user on most, but we opened a joint card for $10,000. Needless to say, when we broke up, I took him off of the cards so he can't charge, but the joint account I had to close because the bank would not agree to divide it in half. Although he verbally assured me that he will pay off half of the joint credit card (some day), it's been a few years and he hasn't paid a dime.