Blackmail her
From Create Your Own Story
"Wow, Callie," you say, looking at the magazine. "Mom and Dad aren't going to like it when they see this.
Callie's face pales. Your mom and dad would really go ballistic if they knew any of you had anything like this, and she knows it.
"No!" She pleads. "You can't tell them. They'll kill me!"
This is your opportunity. Callie knows she will be in huge trouble with your parents if you tell them, so you can probably blackmail her with the magazine. But you suspect she'll balk if you ask for too much initially.
"I won't tell Mom and Dad, Callie, but you have to make it worth my while."
Callie looks at you, innocence on her face, despite what you found her looking at. "What do you want?"