You were out on the front porch of the cabin you and Luffy live at; Luffy has to live far away from civilization because scientists will hunt him down to experiment on him if he doesn't hide. He trusts you though, because you're the only human who has ever seen him as not a monster.

Luffy, flying around the property that is surrounded by thick forest, comes down and lands on the ground with his bird legs, his wings flapping gently as he slows his landing. His only bird features are his bird legs/claws, and his big, dark grey wings.

"Hey! I found a pretty flower! I saw it when I was flying up there... I wanted you to have it!" He smiles so brightly and happily as he hands you the flower.