When a bisexual woman is in a relationship with another woman, she's in a "lesbian relationship," even though she isn't a lesbian. When a bisexual man is in a relationship with another man, he's in a "gay relationship," even though he isn't gay. When a bisexual is in a relationship with a member of the opposite sex, they're in a "heterosexual" or "straight" relationship, when they're not heterosexual. This common and ignored example of language-based biphobic erasure is much more important than it might first appear.
Sexuality As Relationship Status
Language is so incredibly important, because it shapes how we view, understand and interact with different issues that we face, as well as the general world around us.
The use of the term "heterosexual (or straight) relationship" ensures that heterosexuality is seen as the default. If a relationship is "heterosexual," then it must be for heterosexuals. On the other hand, a "homosexual (or lesbian/gay) relationship" is positioned as heterosexuality's opposite, deliberately separated as far from heterosexuality as possible to ensure heterosexual comfort. There's no space left for bisexuality at all. If a woman and a man together reinforces heteronormativity, and two women or two men reinforce homonormativity, then the only hypothetical (and unused term) "bisexual relationship" has to be polyamorous with both sexes included, which defaults to the immediate biphobia that bisexuals are hypersexual and unable to commit to a single partner.
The use of this language innately denies bisexuality and biphobic oppression, because it deliberately pushes and reinforces the idea that bisexuality and bisexual-exclusive experiences aren't real, only heterosexual and homosexual sexualities and experiences are real. Bisexuals are reduced to objects where nothing matters but our partner (or potential partner), and only heterosexuals and homosexuals can therefore speak on bisexuality and bisexuals, since the implication is that whatever we think we experience, only they know the truth.
Homonormative Acceptance of Heterosexism
Despite homophobic oppression, the acceptance and agreement in spreading this heterosexist dichotomy means that within the LGB community, homosexuality becomes and stays the default. This makes it much easier for homosexuals to deny biphobia to centre themselves, and therefore will support heterosexism to at least be "rewarded" with basic terms and hypervisible recognition, despite still being entirely and equally as oppressed as bisexuals. Since the LGB community is homonormative, bisexuals default to homosexual-centred language and judgement, and so thoughtlessly accept submitting to sexuality-based language that erases our own.
When we submit to saying that a bisexual can be in a "heterosexual relationship," not only is that bisexual forcibly re-closeted, they are groomed to submit to their opposite-sex partner and the heterosexist and heteronormative behaviours and beliefs surrounding that dynamic, and every bisexual-specific issue, experience and support needed within an opposite-sex relationship is washed away. That does nothing but make biphobic oppression more invisible, and leaves bisexuals to suffer alone without the help that they need, while being gaslit to believe that they are "oppressors," and so are manipulated to stay silent about all of their struggles.
When we submit to saying that a bisexual can be in a "homosexual relationship," not only is that bisexual forcibly re-closeted in the other direction, the other issues also apply, but in the context of centring their homosexual partner. With the added dynamic of recognising that their homosexual partner is oppressed for their homosexuality, and the biphobic belief that the bisexual is only "half-gay" and therefore only "conditionally oppressed" compared to their partner, there can be an additional layer of accepted emotional and biphobic abuse that's overlooked, or even encouraged from their partner. In both cases, if both partners are bisexual, it encourages mistrust and suspicion between them, damaging them both as they are socialised to treat other bisexuals as potential "sometimes-oppressors."
If we allow others to describe bisexuals as being in "heterosexual relationships" or "gay/lesbian relationships," then either heterosupremacy or homonormativity within the community wins. It supports the same blatant biphobia that says, "bisexuality isn't real and biphobia doesn't matter, only relationships and visible behaviours matter, and the sex that bisexuals date dictates how bisexuals can be erased."
This is a great example of why biphobia is so insidious, because even if you recognise that biphobia is wrong and you deserve equal respect and freedom from oppression, the casual biphobic language has still groomed most bisexuals to subconsciously think, "If I'm in an opposite-sex relationship, I'm in a heterosexual relationship, so I'm basically nothing but heterosexual" and "If I'm in a same-sex relationship, I'm in a lesbian/gay relationship, so I need to remember to think about lesbians/gay men, who are really the important ones here not me," via society's (and then the LGB community's) biphobic gaslighting, which in turn subtly chips away at our feelings of self-worth and self-confidence, because yet again, it's other groups determining our visibility, our experiences and our worth, which means we trust ourselves less, which means that we question our sexualities more, which means more negative mental health outcomes.
The Actual Reality Erased
Whenever a bisexual vents about hurt or anger in being erased, and their relationships not always treated as part of bisexuality, there's a common mockery, particularly towards bisexual women, who are said to be "obsessed with making her straight relationship gay," or "fetishising homosexuality," all to guilt trip bisexuals into submission and subtly spread more biphobic abuse. Sometimes, that's described as bisexuals "ignoring material reality," where only the homosexual reality matters, because of the biphobic, homonormative belief that only homosexuals are oppressed, and if a bisexuals don't perform enough homonormativity, every bisexual-specific issue or experience is erased, nonsensically dismissed as examples of "heterosexuality" or signs of "straight-passing privilege."
The real question underpinning all of this is a simple one: are there any actual benefits to bisexuals in erasing this biphobic sexuality-based language, or is it stereotypical bisexual "attention-seeking"?
If bisexuals in relationships with the opposite sex aren't erased as simply being in "heterosexual relationships":
Biphobic abuse from heterosexual men towards bisexual women won't be erased or buried, and they will be able to access specific support geared directly towards bisexuals, considering the much higher levels of domestic violence they face, instead of being treated like heterosexual women
Bisexual men won't be dismissed, ostracised and abused thanks to the biphobic stereotype that they're "really just gay," but could more openly date and love women without biphobic suspicion
Bi4Bi couples who are closeted for fear of biphobic (and violent heterosexist) abuse will be able to access support from LGB communities
Bisexuals will have the ability to stand up and be literally counted for the likes of governmental assistance or funding for bisexual resources
Bisexuals will not have their sexuality constantly erased to the point that they are gaslit to question and be uncertain about their own sexuality and experiences
There will be space for bisexuals to discuss the nuances of being bisexual and having a partner of the opposite sex, navigating the world in that unique way
Heteronormativity is challenged and bisexuality isn't erased to pretend that both bisexuals and heterosexuals experience the world in the same way just because of who a partner happens to be
If bisexuals in relationships with the same sex aren't erased as being in "homosexual relationships":
Casual biphobic emotional abuse that self-victimises homosexuals in "your bisexuality victimises me because I am homosexual" won't be tolerated, and bisexuals will be able to access support instead of be expected to console homosexual abusers
The biphobic lie that "bisexuals mostly end up in relationships with the opposite sex" ends, and bisexuals can more easily become more visible within the community
Particularly bisexual women who prefer or only want other women stop believing in the deliberately isolating, internalised-biphobia inducing biphobic myth that they're "a minority within a minority" that both encourages them to hate and not relate to other bisexuals, which currently immediately manipulates them into submitting to lesbians instead
Bisexual men can openly challenge the homonormativity that constantly erases them as "gay men in denial" so that they can be visible and share their experiences as bisexuals
Homonormativity within the community is challenged, bisexual-exclusive experiences and understandings can become joint centre-stage, and both lesbians and gay men can fully own their own unique understandings of themselves and their experiences without being made to share that with bisexuals, too
Bisexuals will be able to have an equal voice with homosexuals, our unique experiences can be discussed, and we can better challenge biphobia within the community
If bisexuals aren't stuck within that false "Heterosexual vs Homosexual" dichotomy in general:
Bisexuality as a unique sexuality will be more easily accepted as something entirely separate from both heterosexuality and homosexuality
Biphobia will be better understood as a unique and separate oppression
Specifically biphobic abuse within relationships of all kinds can be discussed, studied and addressed to support bisexuals and help prevent bisexuals from being targeted by exploiting biphobia to control them
More specific bisexual experiences will be counted and understood as unique bisexual experiences, instead of being denied and erased, allowing more bisexuals to connect with each other
Bi4Bi couples who are out challenge the current norms and show that bisexuals can (and often should) partner together, because we understand our own sexuality and experiences more than anyone else ever can
Bisexuals won't have our love, loyalty and commitment challenged because without being erased, others know that we're not one or the other sexuality torn to bounce between them, but individual bisexual people who fall in love and commit just like everyone else
None of the above are exhaustive lists or examples.
What that all boils down to is that without the language there dismissing and erasing bisexuals within relationships, and therefore not dismissing and erasing bisexual-exclusive experiences, downplaying or denying biphobia, and ignoring biphobic abuse, bisexuals - and those around us - are forced to recognise that we can't be shoved into the "straight" or "gay" boxes, because we're bisexuals, and we will never be either of those things, or experience life or even our attractions the same way that heterosexuals or homosexuals do.
This biphobic language comforts heterosexuals and appeases homosexuals and harms bisexuals, and bisexuals need to learn to stop perpetuating biphobia.
If you're bisexual, never refer to yourself as though you're in a "heterosexual" or "homosexual" relationship, because that is the wedge that is deliberately used to sneak in, deny your bisexuality, deny your experiences, and kickstart the process of gaslighting you and making you more susceptible to abuse.
The only reasons that anyone could ever be against the point of dropping those biphobic descriptive terms for bisexuals is because they're biphobic, they don't actually believe that bisexuality is a real and unique sexuality, they don't want bisexuals to receive care and support, and their aim is to erase bisexuals in any way that they can.
Just because there are terms that are normalised, that doesn't mean that they're harmless or should never be challenged.
Be brave and stop allowing biphobes to define you. You'll be amazed at what a change in oppressive language and the ability to correctly name your experiences does for how you can fully perceive your world around you.