First the good news: You don't have to prove bullying in the workplace because your supervisors already know it's going on. Now the bad news: They aren't going to do a damn thing about it because bullying in the workplace is accepted and encouraged as a means of maintaining the status quo.
Sadly, this is the same reason why bullying is tolerated in nearly any and all social structures in our society.
Human beings are a pack animal, and we have innate biological drive to maintain a sense of social order wherever we go. This desire likely traces back to our primitive caveman days, when people lived in tribes. In a tribal environment, everyone has a place or a rank, and this system is reinforced with a shit-rolls-downhill pecking order.
The belief is that picking on those beneath you in the pecking order helps maintain this system of hierarchy. Everyone knows their place and does what they're supposed to do. Thus the "machine" of the tribe continues to work and everyone in the tribe reaps the benefits that tribal living provides - sustenance, safety and protection from outside threats, shelter, etc.
While we might be modern humans, we still live in a tribal society. We just don't recognize it as such. As a human being in today's society, you live in several tribes from your city, state, and country. Your workplace is one of them, and the bullying and pecking order are simply part of what the bosses believe "needs to be done" to keep order.
Don't believe me? Try following the advice that others have given you.
Try to document the bullying. You can write it down, record it on tape, and even videotape these incidents. When you go to management or human resources to report that someone above you is bullying you, you'll be the one who's seen as the problem. Chances are, you'll likely be fired.
Because if you're being bullied at work, chances are good that you're a low-ranking member of your company's hierarchy. Do you really think the bosses are going to take your word over that of someone with a higher rank? Those people are responsible for carrying out the boss's orders, and with that comes a certain amount of trust and expectations.
You, however, are replaceable.
Chances are, the higher ups won't believe you when you try to tell them that you're being bullied by your superior. And it's not like the person doing the bullying is going to admit it. Chances are, he/she will deny it and you'll end up looking like the crazy one. In the end, it's not worth it.
If the bullying is bad, find another job and leave. If you're working 40 hours a week, you'll spend close to 2,000 hours with your coworkers. It's better to find a place that makes this time well spent. Find another job and move on. You always can tell the world about what the bullying that went on when you review your former workplace on Glassdoor or similar sites.
Why is bullying in the workplace so common? Why is it usually the bully who gets the support from management?
It's because bullies are manipulative, social cowards. They manipulate and convince people into thinking that they're the "right" kind of people set for their jobs or career in order to gain suppor...(more)
Just like you handle any other bully at work: by being professional and not stooping to their level. If you can ignore the behavior, start there. If the situation makes this not possible and you can't ignore it, you stand up to him/her, in person, not via email, and not in front of other people. Be professional, do not raise your voice, calmly make the bully understand you won't tolerate being bullied. If the behavior continues, report it
His/her sexual orientation and whether it is public or in the closet, should have nothing to do with your approach to stopping the bully. If you use his/her sexual orientation as a weapon (for example, "outing" the person, you will be the bully.
First of all you need to talk to the bully and ask him/her to treat you with respect.If it doesn't work, your office should have rules about harassment in the workplace.You can make use of it to tackle the issue of harassment.If nothing works, hire a lawyer and take up your case. In our company we were given Workplace Bullying Training Program to prevent such issues.Now a days most companies are providing such training as bullying affects the productivity of employees.