User blog comment:Hulk10/Opinions/@comment-28090612-20160512163654

Well, I kinda understand because for many species such as Dragons, Centaurs, and more old way holding monsters do NOT want their lineag and species' genetic DNA to be broken or "contaminated" from random species and want their respective species to sex with one-another so that their lineage wont bebroken

But it can only apply to (single-gendered) species such as Lamias and Harpies....