The word Fa'afafine, in Samoan, means literally way of a woman or like a woman. It does not, however, refer to females, but to a so-called "third gender" a subset of males who live as women and adopt traditional female roles – household tasks, raising children, caring for the elderly and so on. There is a long-standing tradition of this kind of transgenderism in the Polynesian Islands – in Tonga such people are called fakaleiti, mahu in Hawaii, and rae rae in French Polynesia; it's the Samoan version which is best known, however.
Traditionally, in households without daughters, or with a predominance of male children – Samoan families are big -- one or more of the sons would be chosen to help the matriarch in her tasks, and this boy was then raised as a girl, often to the extent of being dressed in girls' clothing . This daughter-son would continue to fulfil a woman's role throughout their life.
Originally, no consideration was given to the natural inclination of the child in question – it was a simple matter of expediency. The family needed a girl-child, so if it didn't have one, a boy had to carry out the tasks a girl normally would. It was not unusual in that case for the fa'afafine to marry a 'real' woman and have children, although they would not revert to a traditional 'male' role even after that.
Fa'afafine have always, therefore been accepted in Samoan society – indeed they were often celebrated as being a "A daughter in the kitchen and a son in the fields"; acknowledgement that they were capable of, and as need allowed to, carry out the traditional male harvesting tasks as well as the female nurturing ones, something a real daughter would not be permitted to do. They have always had a reputation for being hardworking and useful members of the society.
Recently, however, it has become common for boys to choose to become fa'afafine, if they feel their natural inclination lies to the feminine. They may or may not undergo transgender surgery – generally they don't – but they consider themselves to be female and are generally treated as such. This has added a layer of complexity to the situation. Not all homosexual boys in Samoa become fa'afafine - far from it - and those who do largely don't perceive themselves as homosexual, but as women without vaginas. Generally they have relationships with men who identify as heterosexual, although they cannot marry them, and a man who enters into a long-running affair with a fa'afafine is likely to have his manliness called into question. Relationships involving two fa'afafine are very rare, and in modern Samoa, few, if any, fa'afafine have relationships with women.
This change has made the position of fa'afafine in Samoa more tenuous than it used to be. On the surface they continue to be accepted, and in the capital city, Apia, this appearance generally goes deeper – there, fa'afafine often pursue careers in entertainment, across a spectrum that ranges from "drag queen" to traditional dance, and they're prominent in most artistic fields. In the villages, however, things don't run so smoothly – Samoa is a fairly strict Catholic country, so parents tend to discourage their sons from going down the fa'afafine route. If they choose it regardless, they are expected to keep to certain rules – in some villages, for instance, only 'real' women are permitted to grow their hair long, even while it is perfectly permissible for fa'afafine to wear female clothing, and men who become involved with them are viewed with a certain amount of suspicion.
To an extent, Samoan society has been hoist on its own petard – it's an environment that disapproves of homosexuality by reason of its religion, but at the same time has a long and honoured history of feminising certain of its men. So, while the 'third sex' was easy to accept when it habitually mated with women, the country is still coming to terms with the new breed of fa'afafine – a third sex of men who prefer male partners.