So I have an online PSN account with DLC and I want to make a second online PSN account and I want to keep the DLC. Would the DLC be on both online PSN accounts?
Content downloaded onto an activated console is accessible to all users on the same console as long as the console is activated with the owner of the content's PSN ID. Some content specifically prohibits this.
Content is not shared in the store across PSN IDs and only the account that purchased the content will have the ability to install the content. To share content across accounts, simply have the owner of the content activate the console on their account and install the content on the same console.
For content purchased prior to November 18, 2011, you were allowed to have that content on up to 5 PS3s, and content purchased after November 18, 2011 is only allowed to be installed and activated on up to 2 PS3s.