I think infidelity is defined very differently depending on the cultural and sexual orientation. I mean, it is clear that when it comes to homosexual populations, there is definitely less monogamy in a relationship; however, perhaps more honesty. A lot of gay relationships have a lot of outside partners, and it's something that is very acceptable. Many gay relationships are negotiated in such a way as to allow such outside contact. Of course, cheating is also very prevalent as well in homosexual relationships. It seems that lesbian women tend to be more monogamous, whereas gay men tend to have more sexual partners and more variety of sexual encounters.
And of course this is all due to the same big "T," testosterone. Men have about a hundred times more testosterone than women do on average. So, it's only natural that men have more sexual thoughts, sexual fantasies, sexual desires and urges. So, when we are looking at the homosexual population, it's only natural that two men together will have more desire for outside sexual contact than two women together that tend to get kind of complacent sexually, which is known as actually lesbian bed death, meaning that over time, two lesbian women together tend to have less sex than two gay men together.