Our rather small company shares a slack channel with our larger parent company. Today I came in to work to find that one of the employees of the parent company had posted a "joke" about the upcoming fifa World Cup in slack.
I'm not going to post the joke here, because this question is more about the idea of sexist banter in general, rather than this specific joke (similar sexist jokes have been posted in the past), but in short, the "joke" was demeaning women by implying they are completely clueless about sport, and frankly demeaning men as well by implying we're all sport crazed hooligans.
The joke received a few chuckles and mutters of "it's true though" from some people in the office, however myself, and another of my colleagues, were pretty disgusted by the message and frankly I'm not sure whether I want to work in an environment where that kind of thing is acceptable.
I've considered going to HR regarding it, however there's the issue of "HR is there to protect the company, not the employee", there's also the fact that the instigator is not an employee of our company, but of our parent company, and I'm also fairly sure HR would simply cast it off as "just a harmless joke".
What are my options here? Should I just suck it up and accept that the work culture of this office are okay with casual discrimination? Should I go to HR anyway? Should I confront the instigator directly?