Cock! I like!
A smattered translation of some bits of German (from whatever I can recall from my basic German course two years ago...) that is spoken in the video, hopefully it brings meaning to the humour.
Lady: Sprechen Sie Deutsch? - Do you speak German?
Man on bicycle: Deutsch? Nein. - German? No.
(Turns to the other man) Spretch du Deutsch? - Do you speak German?
Man standing: *can't make out what he's saying... sorry... I can't make out the rest!*
Joker who spends his free time milling around NUS pretending to be a student...