What is a "homologous pair" of chromosomes in cross joining or cross over?
The term sister chromatids refers to the pair of chromosomes which have been produced from a single parent chromatid by DNA replication, while a homologous pair refers to chromosomes which are more distantly related (e.g. those inherited from one's mother and father, which I guess is what you mean by 'male and female chromosome').

So the two options you give are identical, and neither are joined together by a centromere. The sister chromatids are joined by the centromere, while the homologous chromosomes exchange material during recombination (cross over).