She tells him she has some clothes he can borrow

Blinking at him she tries to respond, “Wh- wha-,“ before taking a breath. Thinking to herself she wonders if her teammate is stupid or just ignorant. Hiding a smile she told him, “Come over here, I have some extra clothes you can borrow.”

Taking a scroll out of her pouch she unrolled it looking for a specific spot. Using a touch of chakra on one of the seals lining the paper a poof of smoke surrounds it.

“Woah! That’s so cool! What did you just do Sakura-Chan!?” Naruto asked excitedly.

"Naruto, it's just a sealing scroll," Sakura said before reaching her hand into the dispersing smoke. Puling her hand back as the smoke was gone, she had a pair of orange panties that she handed to Naruto.

When Naruto grabbed the panties out of her hand he commented, “Woah, these are orange! That’s so awesome Sakura-Chan! Thanks a lot.”

Without pausing, Naruto pulled down his shorts without a hint of shame allowing Sakura to see his tiny two inch penis before he stepped into the panties and pulled them up.

Twisting around to get a feel for the underwear, Naruto allowed Sakura to see his bubble butt clad in the orange panties for herself.

By the time she could think straight again Naruto had come back out of his room put his normal clothes on, so if Sakura didn’t already know, she’d have no idea that Naruto was wearing panties.

Knowing his usual manner was to shout things out, she suggested, "Naruto, if you didn’t tell anyone about me helping you out, then Sasuke would know you needed help."

Pounding his fist into his flat palm, Naruto complimented her, "That's a great idea Sakura-Chan, lets get to training!"

By the time training had ended, Sasuke and Kakashi were quick to leave the training ground leaving just Naruto and Sakura.

When Naruto made a curious sound and looked at Sakura like he wanted to ask a question, she told him, "It's fine Naruto, lets go back to your apartment and then you can ask your question."

When they got into his apartment, Naruto asked, “Umm, so about the underwear Sakura-Chan?”

"Huuugh, it's fine Naruto, you can have that pair, but you owe me a favor," Sakura told him.