Staff at Soho production company, MJZ, filmed the pair engaged in some nookie on Wednesday afternoon and then posted the video on You Tube.
The 'Sex and the City' clip has received thousands of hits on the video sharing site and has been viewed by people in Australia and New Zealand.
A producer at MJZ said she was shocked to look out from her 2nd floor window and spot the pair engaged in their sunshine romp.
She said: "I was working away and looked up and saw this bloke and a girl in the doggie position going at it on top of a building across the road.
"I couldn't believe it, I started laughing and shouted to a couple of my colleagues and then one of the girls grabbed a camera and began filming it.
"They were going at it for a good ten minutes but stopped a few times in between for a well earned break."
During the 30-second clip a male voice says "this is insane" before a female
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