– Genuinely Curious
Same sex marriage is now the law of the land, so I can only assume you are referring to bisexual people in opposite sex marriages, GC. The short answer is no, and that notion is one of the many myths about bisexuality. The sex or gender of your partner does not determine your sexual orientation identity.
If what you propose were true, all sex work – porn, sex or domination for money, exotic dancing, etc. – would come to a crashing halt. Extramarital affairs wouldn’t exist. Heck, the Bible wouldn’t be nearly as thick with stories of infidelity! People don’t stop being attracted to other people once they get married. That goes for monosexual folks, too.
Another example: gay people who get married and have kids for the show, to maintain privilege & power, or because they’re told they’ll go to hell otherwise. You don’t stop being gay because you want to stop being gay or because you get into a different sex marriage and have a few kids the old-fashioned way. This is one reason straight conversion camps are such big money-makers – the “relapse” rate is high when you’re trying to stomp out a part of the brain that also controls things like hunger, sleep, and thirst. That’s super-simplified, of course, but it’s true that people who try to fit into a societal scripted sex or gender identity usually suffer psychologically for it.
So, just because someone is bisexual, pansexual, demisexual, sapiosexual, or even asexual, does not mean that they stop being those things when they are in a monogamous marriage to someone of another sex.
For me, I like to say I’m queer, for brevity purposes, but also because it lets me define what that means to myself. It’s generally understood a queer person isn’t strictly attracted to people of a different sex . The real issue here is how uneducated most people are on sexuality as a science. Many people search for years to find words to put to their identity, and often we must choose the descriptors that we know that best match us. We define our sexual identities. They do not define us.
I encourage you to read the information provided in the links above, and seek out more information on your own. It’s up to each of us to be aware of our own blind spots and learn the best ways to be allies to marginalized groups we’re not a part of. Sometimes, that’s the most important work you can do as an ally. That, and educating others.