Nagato and Khana had sex. They never had kids because Nagato was sterile.
And then Sai and Naku appeared with their five children, completely ruining their alone time. Just as planned. Because they were bored. Yep. They were bored.
Itachi jumped through the window, dressed as Tarzan. He grabbed Khana and ran away. Nagato was sad.
Sasuke dashed through. He was after Itachi, as per usual. Oh, and he wanted to save his sister figure, I suppose. Anyway, Nagato was still sad. So Sai poked him.
Then Nagato smiled. Then realized he was still alone sexually. So he sat on the bed and stared at the remnants of people, waiting for people to leave. Naku left but Sai stayed. Staring.
Khana walked in, Itachi-Tarzan passed out over her shoulder. She dropped him in the hallway, picked up Sai and placed him next to Itachi. Khana and Nagato then proceeded to have sex (copulate) once again. Sai left. Kakashi came across Itachi as he was walking by. He stared silently.