Lol, i just finish to read this topic and i confess, i laughed so much with the "disturbing couples".
Well, love in One piece ?
Let's make a try :
Luffy : only in love with his dream : to become the pirate king.
Nami : in love with money. (and gold, jewel..etc…) I don't think that Nami have a romantic interest for a guy from the crew. And she will never have IMO.
Zoro : his priority in the life seems only to be : beat Midhawk to a pulp !! so….....
Sanji : tell him that a table is a girl and he will fall in love with. Not the "one-woman" kind of guy.
Usopp : Kaya i guess.
Robin : very calm, very cool, distant like Zoro, Maybe a sign…..
Chopper : errrrrrrrrrrrrr, Joker !!
Franky : terminator in love ? well, who knows ?, maybe one day. ^^
But anyway, Oda makes that clear.
The adventure is the only one they are in love with.
Disturbing couple :
Mister two & Igaram
Pretty twisted. ^^