Our bodies are designed with systems that have a specific purpose, and nature reacts when those systems are used improperly.  Sometimes there's a defense mechanism, such as, e.g., vomiting; other times a vulnerability is created whereby another organism takes advantage, such as reduced immunity allows pneumonia to develop.  The multitude of STDs, diseases unique to the sex organs, is indicative of nature's specific intention to avoid misuse of the sex organs.  Multiple partners, sodomy, etc... all increase the spread of disease, regardless of the sexes abusing their organs.  

Most people will avoid risk taking when it comes to sex, but for some reason homosexual men have shown the distinct inability to control their behavior.  STDs run rampant in the homosexual male culture compared to straight culture.  Call it nature, call it God, but the signals are clear, AND the diseases are all avoidable with proper conduct.  What's absurd is that the conduct continues.