Barr bodies in males?
To understand how the X inactivation can occur in, it requires a bit of understanding of how Barr bodies come about. 

The main key players to keep in mind are (From 1):


Xist: Xist   Required for initiation of X-inactivation
Tsix: Tsix (It's Xist spelled backwards!) Represses Xist expression by silencing the Xist promoter, also required for X-chromosome pairing, counting the number of XICs (X-inactivated chromosomes)


From 2, Here is a general diagram of how X-inactivation occurs. 



X-inactivation requires first, count how many X chromosomes are present (n). Then, the (n-1) number of X chromosomes are inactivated. The choice for which gets inactivated is largely random. 

Therefore, if a male has multiple X-chromosomes (as in the case of Klinefelter syndrome) then X-inactivation would occur in males. However, there is also the case that erroneous counting may lead to the inactivation of the only X chromosome in males early in a developing embryo. But this is lethal, and the embryo would die. 

More about Kleinfelter Syndrome can be found here: Klinefelter syndrome


Guided by RNAs: X-inactivation as a model for lncRNA function.
Lessons from X-chromosome ina ctivation: long ncRNA as guides and tethers to the epigenome