I nearly came out as trans at work, then heard awful transgender slurs
I started a new job in the food and drink industry, and got to know people quickly - because I worked hard and stayed out of the workplace politics, my managers liked me and very soon stopped watching what they would say in my vicinity. Because they saw me as 'on their side' they would regularly criticise and insult my coworkers behind their backs, call customers sexist and racist names, and openly play favourites with the staff roster.
Slurs against transgender people
One day, a manager started talking about a trans woman who had recently interviewed for a job with the company, and almost immediately it became a slew of vicious insults, slurs, and incredibly personal, nasty comments about the woman's appearance, body, lifestyle, sexual history, etc. I am transgender myself and had been struggling over whether to come out at work before this happened.
Hearing this, I excused myself to the stockroom and spoke with one of my colleagues, who knew about my situation and had heard all the manager's invective. We discussed what could be done, but as the whole management team regularly took part in the same nasty culture, there wasn't anybody we felt we could complain to without jeopardising our jobs.
What I did
We spoke to the rest of the floor team about what was going on - most people were already aware of the culture problem - and many of us left the company. I handed in my notice and was gone two weeks later. It's been just over a year since then and the management team are the same, but they seem incapable of holding onto staff.
Many people in the industry will be eager to convince you that bullying, racism, misogyny, homophobia etc. are just 'part of the culture' and shouldn't be taken seriously - that you should grow a thicker skin or a sense of humour. It's simply not true. It harms real people, it encourages callousness towards customers and coworkers, and sooner or later it ALWAYS becomes personal. Trust your gut and treat the 'jokes' as symptoms of a real underlying problem.
Supporting each other
My coworkers were wonderful people who were aware of the culture problem and equally disgusted by it. When things got out of hand we were all able to come together and discuss a solution, and we supported each other both emotionally and over the course of hunting for new jobs. When management are toxic, solidarity with your colleagues is irreplaceable.