Would not budge

"I couldn't see what was inside, but the engine was left running,"Ms Kok said.

Her husband rapped on the car window to ask its occupants to leave, but they wouldn't move.

"A transvestite rolled down the window and told us in a manly voice that they were not doing anything wrong. Of course, I had a shock."

Yet that's nothing compared with what happened three weeks ago, said Ms Kok.

She and her husband returned home at 3am one night and spotted a silver van parked at the dead end of Upavon Road, with its engine running.

Irritated, they decided to confront the driver. But the driver, who seemed to be in his 50s, retorted:" How do you know I am having sex here?"

When Ms Kok took out her camera phone to take a picture of him, he started shouting and appeared threatening.

"He even tried to scare us by revving his engine," Ms Kok added.

The pretty woman beside him looked like a foreigner, Ms Kok said. "She was the one who calmed him down."

They later left.

Ms Kok called the police, and for the next two weeks, there were no more condoms left along Upavon Road, she said.

But last weekend, such litter appeared again near Ms Kok's doorstep.

That was the last straw. She took pictures and sent them to The New Paper on Sunday.

"This is too much," she said. "It's like an orgy happening near our house."

Her neighbour, who wished to be known only as Mr Cochard, is also upset by the sexual activity disturbing the residents' peace at night.

Said the 45-year-old, who has been living there for six years: "They are very rowdy. Some even come in threes.

"They make out, laugh and smoke in their cars all the way till the wee hours."

Mr Cochard, who is self-employed, said such cars - and occasionally, trucks - are parked there "every night of the week", not just on weekends.