Please explain if it is possible for an xx male to have uncharacteristically large genitalia?

Confusing. XX chromosome defines female gender. XY is male. If you mean a man with two Y chromosomes or XYY, these individuals may be taller than average but have no other unusual physical characteristics. Men with XXY genotype or Kleinfelter's syndrome typically have smaller than average genitalia. Thanks for trusting HealthTap!