SOMEWHERE between Abu Dhabi and Lusaka, the US's most powerful diplomat sat down with her closest aide last week and talked of straying husbands, predatory women and internet sex.

It was not quite what Hillary Clinton had intended when she set off on her latest tour as US Secretary of State; yet it is hard to think of anyone in Washington better equipped to offer advice on the painful fallout from a sexual scandal.

For once, the shenanigans had not involved Clinton's husband, Bill. Yet the saga of congressman Anthony Weiner's penis and how its picture turned up in cyberspace has crushed one of the Clintons' most cherished acolytes and added a poignant human twist to an otherwise farcical tabloid tale.

She is officially Hillary's deputy chief of staff but Huma Abedin, Weiner's clever and glamorous 35-year-old wife, means far more to the Clintons than her title suggests. Hillary once described her as "a second daughter" and when Abedin married Weiner last year, Bill presided over their vows in his capacity as former president.

Abedin was a political intern when she joined Hillary's staff 15 years ago. She grew so close to the then first lady that rabid Clinton-haters began to spread false rumours of a lesbian affair.

When Hillary ran for a Senate seat in New York, Abedin went with her. When she joined President Barack Obama's cabinet, Abedin became one of the few Clinton advisers who had worked at both the White House and the State Department.

Last week, she experienced a less enviable aspect of life with the Clintons, as her husband bumbled his way through pitiful lies and tearful apologies for his so-called sexting habits.