manky tango
A Scottish term for when two people engage in any kind of dance which leads to sexual intercourse between the two. However the dancing must continue, this is done so other people don't notice and are simply convinced that they are dancing. If the dancing were to stop, it would no longer be a manky tango, it would simply become sex
"Aye, that party was mad last night- Jessica and Gavin had a manky tango on the dance floor"