Couples made up of two men or two women have much more difficulty adopting abroad than heterosexual couples or single people.
However, some of the countries that allow intercountry adoption for gay couples are the following: Brazil, Colombia, Mexico (in some states), South Africa, etc.
There are many more countries where gay adoption is allowed (Germany, Belgium, United Kingdom, Portugal, France, Ireland, etc.), but this is hardly contemplated because the number of adoptable children is very small and domestic adoptions have priority.
Read the full article on: Which Countries Can United States Citizen Adopt From? ( 26).