Tsunade walked right in. She saw Sakura naked and covered in cum and Naruto and Sasuke standing there naked.
As turned on as she felt, she had couldn't just stand there. She had to say something

"What the hell is going on here!? Are yo... are you RAPING her??"

"No lady Tsunade!" yelled Sakura. "It's not that at all. We.. we're just having... fun."

"All of you are so goddamn young! Do you know how much trouble you three can get into?"
The three of them shaked their heads with a scared look. Tsunade noticed this.

"Well, there IS a way you won't get in trouble at all"

"What is it? asked Naruto.
"Yea, whatever it is we'll do it!" said Sasuke

"Oh really? Well then..."
Tsunade started undressing herself and layed on Sasuke's bed.

"Im all yours. Pleasure me to my fullest. Make me cum like I've never came before. ALL of you. And then I just MIGHT forget this ever happened," explained Tsunade.