"The Worst Three-Legged Race" (二最悪の二人三脚, Saiaku no Nininsankyaku) is episode 194 of the Naruto: Shippūden anime.
Sakura and Naruto see Kiba and Akamaru delivering some items. Sakura commented on how Naruto and Sasuke were inseparable when they were younger and Naruto suddenly remembers the early days when they were on a mission to retrieve a golden statue, which was stolen by a band of thieves from a daimyō's sister. As Naruto and Sasuke retrieve the statue, Sakura gets taken hostage. At first, Sasuke insists on continuing the mission, but Naruto reminds him that Kakashi said those who abandon their friends are worse than scum. When they finally find Sakura and the bandits, it was at first hard for them because their hands were stuck together. However, the two learned to how to fight as a team and they quickly defeated the bandits and their leader, Jako. Although their mission was a success, the statue itself was very damaged, thought Kakashi suggested that it could be melted down and re-casted. When Naruto complained about his hand being stuck to Sasuke's, Sakura said that it will crumble and fall apart within two or three days, much to the two's disappointment, as Naruto had to go "number two". Sasuke was aghast at the idea, only for Naruto to reply that it was fine since they already peed together, much to Sakura's shock. Meanwhile, Kakashi was content that the two embodied the shinobi principle of never leaving a comrade behind.
For the second time in the series, Naruto and Sasuke accidentally kiss on the lips.
The scene when Sasuke wants to continue the mission without Sakura and Naruto says "Shinobi who abandon their comrades are worse than scum!", is a direct referral to Kakashi's and Obito's conversation about Rin in the Kakashi Gaiden, the same line Kakashi used on Team 7 after they "failed" their Bell Test.