The video shows the clearly identifiable couple engaging in sex acts as they sit in a carriage on the Epping route before hopping off at Reservoir Station.
At least two unsuspecting passengers can be seen in the background.
The pair then take their raunchy behaviour to another public location: Edwards Lake Park, which is a popular spot for children and families.
The video was uploaded to a popular porn website, amassing more than 200,000 views.
If caught, the couple could face a $563 fine each for their sleazy production.
http://news.ninemsn.com.au/national/...elbourne-train