Well, different countries, different traditions, different laws. If you have ever wondered on the specific rules on when you are allowed to fuck who without getting fucked yourself, you might want to check this extensive chart on AgeOfConsent.com.
As the chart contains information on all three possible gender combinations (country notes include information on sodomy laws as well) it is also quite illuminative on where gay people are still having a bad time. It is mostly islamic countries where the trouble is but even countries like Jamaica and Trinidad & Tobago are less relaxed than you might expect: gay sex is just illegal (if the chart is right) in these places.
There is longer explanation on the situation in Germany in english and german.