A/N: There is not nearly enough Sunnyshipping (aka all of the Straw Hats are one big polyamorous crew) out there and that needs to be rectified immediately. Also I haven't written enough from Robin's POV. So here's a short drabble that attempts to fix both of those problems. Not too NSFW; there is way more talking about sex than actually sex.
Robin is no stranger to sex. She has had sex to bribe and to persuade, to pay a debt, to stay alive. Sex has never meant anything to her but just another way to survive.
It has never meant love.
When she first begins to travel with the Straw Hats, she does not think of sex. With them, at least, she doesn't think she'll need to use sex to stay alive.
Still, she has eyes all over the ship. She's always needed to see all to feel safe, to be safe.
She is flustered and shocked in a way she rarely is when her all-seeing eyes first see Luffy, Nami and Zoro making rough love in a tangle of limbs in the bath-house. She withdraws her eyes in a moment of flustered panic and holds herself and wonders if she judged this crew wrong.
Later, she sees Zoro pressing Usopp against the side of the crow's nest. They kiss deeply, grinding on each other, panting into each other's mouths.
The next day, Sanji is pinned between Luffy and Nami's bodies in the kitchen storeroom. They fondle him and kiss him and strip him of his clothes, and he breathes heavily into Nami's shoulder and bucks against Luffy's hips behind him.
That night, Chopper lies in a sleepy pile of his crewmates' arms on the ship deck, a pile of lazy kisses and cuddles and easy laughter. Robin sits in the tangerine grove and observes.
It is only after Enies Lobby that Robin finally allows herself to melt into her crewmates' open arms. She allows Luffy to kiss her ferociously on the mouth, allows Zoro and Usopp to wrap her in warmth and strength, holds Nami's naked body pressed against her when they sleep, watches Sanji melt at her touch, cuddles Chopper tightly to her and presses kisses to his forehead.
Soon, Franky is being kissed and cuddled and coddled and made love to as well, and then Brook, and finally Robin realizes that sometimes she can't tell where her body ends and those of her crewmates begin. She glows with their touch, their feel, their scent.
Robin is no stranger to sex. She has had sex to persuade, to bribe, to survive. And she has made love to those who love her as passionately, as unconditionally as she loves them.