The perils of cross-cultural dating: An agitated Tongan father on finding his teenaged daughter and her Maori-Pakeha boyfriend in her bedroom. "In Tonga, you'd be shot for this," he lectures the startled young man.

The teenagers had been talking and listening to music, innocently enough, with the door wide open, and in full view of the girl's mother. But a cultural line had been crossed, unbeknownst to his mortified daughter and bemused wife: in Tongan society, a girl's bedroom is off-limits even to her own brothers.

Cross-cultural relationships aren't for the faint-hearted.

Many years ago I met the son of a prominent Maori leader, who told me that he and his brother were expected to marry Maori girls. I think he meant to douse any expectations I might have had, which I would have appreciated if I'd had any interest in him. Better to know up front how welcoming the family of any potential suitor might be. As every Polynesian knows, you don't marry an individual; you marry his entire whanau as well.

His family was immersed in Maori culture, and he and his siblings had been raised to speak fluent Maori, to be well versed in tikanga, to see themselves as upholders of things Maori. This was critical back in the early 1980s when te reo was in danger of dying out, and Maori aspirations needed dedicated foot soldiers. Marrying a non-Maori might have distracted them from their cause; it might have weakened their efforts.

A Samoan father I know makes no secret of wanting his daughter to marry a Samoan. As well as all the usual requirements (that the future son-in-law have a clutch of university degrees and be rich), he wants a man who can speak fluent Samoan and be "culturally competent".

That tends to limit the pool somewhat, but he's determined that his daughter will have a soul mate who values her cultural inheritance as a Samoan; he doesn't want her Samoan identity swallowed up by a dominant majority culture.

I hope he's prepared to be disappointed; around half of all Pacific babies born nowadays can claim more than one ethnicity.

Does he have a right to his personal preferences? Is he racist? How you answer that depends on the importance you place on the preservation of distinct cultural identities.

If my father ever harboured similar ambitions, he never let on. Whoever you love, I love, he'd said. Which was a good thing considering four out of five of his children failed to marry Samoans.

I married the first Tongan I ever met, which was quite a feat as there were so few in Wellington at the time. I didn't know then that Samoans and Tongans weren't supposed to get along, though plenty of people have been at pains to tell me in the years since, including a few Samoan males who seemed to take it as a personal insult that I had chosen from outside the tribe.

The truth is that culturally, we're not that far apart.

Mixed marriages are complicated affairs, and anyone who thinks otherwise should read Carol Archie's 2005 book, 'Skin to Skin', which looked at Maori-Pakeha intermarriage and the mixed-race children it produced.

Ironically, most of the couples that Archie profiled were reluctant to recommend cross-cultural relationships to others; even the children produced by those pairings told her they preferred to marry Maori. Archie said many had been put off by the degree of compromise required in a mixed marriage, particularly on the part of the Maori partner, and they weren't prepared to sublimate their Maori side by marrying non-Maori.

Some had grown up watching their parents' struggles, and knew how painful such relationships could be. The singer-songwriter Moana Maniapoto's Pakeha aunt cut her father out of every photo her mother sent her. Ranginui Walker's Pakeha wife, Deidre, had her name cut out of the family Bible by an uncle. In one case, a Pakeha mother referred to her daughter's children as "black bastards".

My own observation of mixed marriages is that the stronger the identification of one partner with a particular cultural identity, the more critical it is to find a culturally compatible mate.

Being somewhat hybridised, I've never been that fussed.

Of course, I understand what it is to not have to continually explain yourself. I understand the desire to maintain language and the best cultural traditions.

I don't want my children bringing home people who don't agree that looking after ageing parents and in-laws is important. Nor anyone who has a problem with the notion of family, and familial obligations, extending beyond the nuclear unit.

But I don't care how fluent and culturally competent my children's prospective partners might be. I've known too many puffed-up purists with lousy values to ever believe that cultural competence equals character.