He was Wearing a Pink nightie

As Luffy tried to calm himself down after the dream, more like nightmare to Luffy, he had and looked to find Nami and to his relief, she was still asleep.

'That was scary!' thought Luffy. 'I can't believe I was going along with her weird photo model thing in my nightmare.'

As Luffy thought, he happened to glance down and saw that at some point, Nami had removed his vest and pants and replaced it with a pink nightie that fit snuggly against Luffy's altered body; after the dream he had, Luffy for sure that this would be another outfit fit for posing in Nami's mind.

He turned towards Nami and just thought, 'Why? Why is she doing this to me? I was minding my own business, on my journey to be the Pirate King, and she just takes it all away.'

Luffy was trying to get the courage to run away while Nami was sleeping, but he was having trouble getting his body to get out of bed.