In fact, 'mad on you' is not nonsense. It just has a totally different (+ve) sense.
b
PS And I'm not sure I'd call 'p*ssed a 'swear word', although it's certainly a vulgar one - best avoided, if only because it's seriously ambiguous. 'He is p*ssed' means 'He is angry' in Am Eng, and 'He is drunk' in Br Eng. The commonness of Am E speech on TV/film/video is making the American sense more common even over here, so that there is no longer a clear distinction between the two - more scope for ambiguity.