Human sexuality is complex, highly sensitive and usually deeply personal. Clearly, one aspect of it in particular is still very divisive.

Two weeks after New Zealand became the 13th nation to approve gay marriage, homosexuality remains a dominant topic for letters to the editor and the online commentariat.

Now, the decision of United States professional basketballer Jason Collins to throw open his bedroom door to the world by coming out as gay gives an age-old topic fresh legs internationally.

Links to the progress made by black sportsmen - almost non-existent in professional sport in the US until the late 1940s - and gay rights were quickly made in the wake of the Collins announcement.

Collins happens to be both; and his decision to speak out has been lauded as brave and a sign of progress towards equality by some, and condemned with typical intolerant rhetoric by others.

It is interesting to consider what the response will be in this country when an All Black takes a similar leap of faith and goes public on his own homosexuality. That none have yet felt ready to do so says much about the prevailing climate in this country, regardless of official state sanction of gay relationships, and now marriage.

Former fullback Allan Hewson attracted derision and contempt from fans simply for donning fingerless gloves and nylon stockings in an attempt to keep warm on bitterly cold winter days in the early 1980s - not that there is any suggestion that he is gay.

Not long ago, boys wanting to play football, basketball or hockey rather than rugby risked being labelled "poofs". Those who identified as homosexual ran the gauntlet of a homophobic society daily.

Fortunately, society is becoming more accepting, especially among young people. Football player numbers have soared in the past decade, and not only at junior levels. Basketball aside, men are now playing netball. Gay support groups flourish in colleges around the country. Despite the entrenched attitudes of some, homosexuals are less likely to be the targets of vicious physical attacks by bigots simply because of their sexuality - although thuggery is still too prevalent.

Supporters of the gay marriage legislation were quick to praise it as a symbol of a liberal and tolerant nation. Which it is. However, that is not the full picture. In a truly accepting world of equality, sportsmen like Collins would not feel the need to overcome their fears and speak out. "I thought I had to live a certain way," he writes in Sports Illustrated. "I thought I needed to marry a woman and raise kids with her. I kept telling myself the sky was red, but I always knew it was blue . . . No-one wants to live in fear. I've always been scared of saying the wrong thing. I don't sleep well. I never have."

The mark of a liberal and tolerant society would be one without pressure to hide from the world in this way. "Admissions" like Collins' would be treated with a yawn rather than celebrity-status attention.

When will the first gay All Black speak out? How will he be treated by coaches, team-mates, opposing players and the public? How much longer until such an announcement would draw no fuss at all?