The actual Hetalia series contains no gay sex, although it has a bit of implied shounen-ai. There are Hetalia /doujinshi/ containing gay sex, but not in the REAL series.
Tnhnhn, no it's not porn. That's hentai. The mistake has been made. Several times, actually.
Hetalia is a comedy about anthropomorphic nations and making serious things in history really quite funny. Except the American Revolution. That made us cry TuT
(Although, there is a very large and sturdy base of Hetalia yaoi fans who wish it was porn //shotseveraltimes)
^Ignore that comment ^.^;
People seem to mix up Hetalia and hentai a lot because of the way they're spelled, they both start with "he" and have t's, a's and i's. People think that they're the same XD