MR BIAN Sin Teck, 64, is nimble on his feet. He can do the merengue, salsa and cha-cha in perfect time with Madam Anna Tay, his dance-instructor wife.

He keeps in step with her in the bedroom too, with the help of Viagra.

'I take it only when I need it, not all the time. Maybe once in two weeks, and just half a pill is enough,' the librarian with Singapore Technologies lets on candidly.

He started using the little blue pill about four years ago, when erectile dysfunction started derailing their sex life.

'I talked to my wife about it and she suggested that I seek medical help,' he says.

Madam Tay, also 64, says: 'We have been married for more than 40 years and can freely discuss this. It's very normal for a married couple.'

The doctor told Mr Bian that his testosterone levels were low and suggested hormone therapy as well as Viagra.

Madam Tay had no objections. The couple have a 40-year-old businessman son and a daughter, 38, who works for toy maker Lego.

They also have a two-month-old grandson.

'It's important for a couple to have a loving and physical relationship. And since the doctor recommended it, why not?' says the chirpy, youthful woman - who heads the Happy Arts Performance Group and has participated in several talent and beauty competitions, including Mrs Singapore.

She adds: 'I go for hormone replacement therapy every half a year too. It's good. It keeps my energy levels up, and I feel very youthful. The dance choreography for my classes is very energetic, you know.'

Madam Tay teaches at community centres several times a week and also conducts dressmaking courses.

The jovial Mr Bian says with a laugh: 'Initially, I was apprehensive about the side effects of Viagra. But the doctor told me it was safe. He even taught me how to use it - chew before swallowing.'

Besides Viagra, he also uses Cialis and Levitra.

'I'm open and even talk to my friends about it,' he says.

He knows that many ageing men philander after getting new sexual energy from Viagra.

He turns serious as he says: 'No, no, not for me. I love my wife very much. We've been married for over 40 years.

'You can't cheat. You have to work to keep a marriage alive.'

As for Madam Tay, she's not afraid of her husband straying.

'He won't, he's a very honest man,' she says.

'Anyway, I'm very energetic. I can keep up with him.'

This article was first published in The Straits Times on May 3, 2008.