Forlooning is an extension of Docking. Where a couple that is engaged in Docking start to urinate.
This would cause the forskin to balloon, hence the word For(eskin)(bal)loon
Timmy and Tarquin were enjoying a spot of Docking and wanted to take it one step further. Ensuring that there was adequate floor covering they started forlooning. It was a fantastic wet mess of cum and pee.