Diandra's Explaination

 In the morning, Nathan, who had been asleep for about 10 hours, slowly woke up while taking a deep breath. He also rubbed his eyes with both hands before opening them.

Nathan then opened his eyes, he then yawned to throw away the sleepiness.

Shortly after that, Nathan realized that he was not wearing any clothes on his body, so he turned to his right and was surprised because Diandra was next to him. Nathan was even more surprised when he realized that he and Diandra were now in one blanket.

Diandra deliberately covered himself up to the bottom of his armpits, so that he seemed naked like Nathan, even though he was wearing a bra without straps and a pair of underwear.