Gamesharing on ps3 with my brother.?

How do you do it? Is it illegal? Ive browsed many questions on here but am finding two different answers. My brother has the first strike black ops DLC pack from like almost two months, I bought the Escalation map pack. He moved out to college and we both have ps3's. How are we able to share these map packs without being banned ? 15.00 is not worth our systems to be bannned. Please let me know with any feedback, i read about gamesharing tonight so im fairly new to this concept.