Why does being LGBTQ+ always have a stigma with being unfaithful in relationships?

Iv never found this to be true I'm 41 and have been gay my whole life and being unfaithful hasn't been a issue !

The stigma may have started with non-heterosexual people who were pressured into heterosexual marriages. This would likely be emotionally damaging to them, and they may have ended up seeking emotional validation from other non-heterosexual people. Due to homophobia and similar, this act would be demonized far more than a heterosexual affair, and may have led to further ammunition for people's unjust hatred. People love to use false stereotypes to justify demonizing something (or someone) they've no logical reason to demonize. It's a defense mechanism for those who are afraid to consider the possibility that they may be wrong, a bad person, or the cause of a problem. Admitting your hatred is unfounded and working to correct it is often harder and scarier than holding onto that hatred. And so, people focus on and exaggerate evidence that supports their hatred, forming and maintaining stigmas and harmful stereotypes. Because people choose, consciously or not, to shut their eyes and ignore the vast amounts of evidence that are contrary to their hateful views.

Anything that's not the typical heteronormative relationship seems to get a bad reputation, due to the fact that people simply think it's "different." People assume if you're bisexual/pansexual, that you will cheat on your spouse with the other sex/gender. If you're gay/lesbian, people simply think you're an insatiable being, and will want more than one person. Pretty much, these assumptions have everything to do with our society being that of a heteronormative society, and anything against the norm is bad/understood, which leads to these stigmas and preconceived notions.

In my own personal opinion, i do believe that this can be down to those who disprove of those who are LGBTQ. I think many people assume this, and sometimes say it without knowing facts to try and put this negative stigma on our/my community. However despite this rates of successful marriages of those who are LGBTQ are higher than those of heterosexual couples.

Because when the community was starting to come into the spot light people always assumed that if they knew someone who was in the LGBTQIAA community that was unfaithful that all people in the community must be the same way.

I think it is because they are seen as sexual deviants and to some people it seems like they have no limits in their sexuality, so they assume they dont have any in a relationship either.

Now, I'm not saying that this is correct or good or anything, but it's only recently that LGBTQ+ individuals have been allowed to marry and anyone, regardless of sexual/romantic orientation, is less likely to be faithful to their partner/significant other when not committed in a serious bond such as marriage. Individuals who live together but are not married have no legal commitment to stay, thus lessening the consequences of leaving.

The LGBTQ+ community is still a fairly new concept to society in general. Anything negative that happens will bring much unwanted attention.

Because it's 'not common' and people are always looking for an excuse; a way to be judgmental and rude.

Because people somehow think that being an Lgbtq+ is all about sex so they think you'll keep seeking that which is absolutely not true as an lgbtq+ person wants the same things out of a relationship as any other human; love, partnership, and intimacy