>> Sure - but it's only offensive if they say it is. In effect, YOU can't
>> find it offensive or declare it to be so unless YOU are offended.
People are only offensive because they know the other person will be offended. NO point in being offensive otherwise. One does not need to be told on meeting someone "will be offended by x"
Therefore I can say xxxx is offensive* because I know it will offend yyyyy. Thats nothing to do with being "offended on someone else's behalf" or being "one of the professionally offended" ( a phrase only uttered but the racist biggots to excuse their behaviour)
*I will concede however that some people have no idea on earth where that line stops and expand it well beyond scope. Most normal people however know.