This is also something most people simply do not understand. The vast majority of all "gay" marriages are as you said, "Shams". (Elton John is an example of this.) Most people think that gay "married" couples exist as people devoted to each other within the confines of their relationship.
The vast majority of them are "open" with both individuals cruising the internet and gay bars looking to hook up with other queers. Promiscuity is part and parcel of the "gay" lifestyle.
Indeed, many gays have put forth opinions that it is essential to being gay, and that people devoted to just one person are not genuinely gay.
How do you educate people? They refuse to deal with this reality.
Look at Andrew Sullivan! Came to this country a clean-cut conservative and within a few years of enjoying licentious America he ended up with HIV, arrested for openly smoking pot in a public park (why was he in the public park?), became addicted to steroids, studied Sarah Palin’s ovulation charts so closely he was disinvited from most tv programs, is in an open ‘marriage’, bought a couple of beagles (today’s go-to dog for gay men), and grew a beard that makes him look like he has 1,000 bees on his face.
Is there an upside to his life, lol?