Suggeset you view;
Worldwide Ages of Consent
World wide the ave age for m/m sex is 16. What is amazing is the number of US states where it is 16 or (even Texas) - 17.
Also see note 18.
"It is illegal for an American citizen or resident to have sex in another country with someone aged under 16, unless the age difference is less than 4 years, in which case the minimum age is 12. "
The Feds do not control the world - and laws on making porn are different from engaging in consentual sex. I suggest you relocate your domain to a realistic location like Denmark or Sweden (15), Australia, UK or Netherlands(16). Even communist China is 14 along with Colombia, Croatia and Ecador!!
So statistically I think you will find that most teens would not be classified as "underage."