Full context: I've been at my job for about a year and have formed close bonds with a number of people, including my coworker "Josh". A new position opened up recently that Josh's spouse, "Jessica", was a perfect fit for, and she ended up getting the job. The day after Jessica got hired, Josh found out that she's been having an affair with one of her old coworkers for almost a year. Josh is filing for divorce and has asked Jessica to resign, but she refuses and showed up to work the next day like nothing was wrong. I know all this only because I'm close to Josh - most people in the office are unaware of these details, and might not even know yet that Josh and Jessica are splitting up.
I approached a friend of mine in HR immediately and was basically told that as long as neither Josh nor Jessica bring their "home problems" into the workplace, it is not the company's problem and there's nothing that can really be done. I was also told that if I was to spread rumors about a person that I could be liable for workplace harassment or bullying - that is to say, if I talk to anyone in the office about Jessica's infidelity, I could be in big trouble.
I'm burning up inside and I'm having trouble concentrating on my work - we're in a small office and it's hard to sit 30 feet away from someone who did something terrible to a friend, then act like nothing's wrong. Josh has not been in to work since the incident, but I can't really imagine how hard it's going to be for him when he comes back if Jessica is still here. Jessica is walking around the office with a smile on making new friends and no one knows what she's done - I want to tell everyone what's going on and what a terrible person Jessica has been to Josh, but I love my job and the people I work with and I don't want to get in trouble.
What should I do? I wish I could just focus on my work and forget about it but my empathy for Josh is holding me back from that. Infidelity might not be a big deal to everyone but it's something that's very difficult for me personally to brush off, especially when my friend is a victim of it. I'm incredibly uncomfortable and I wish there was a resolution to this problem, but I'm not sure there is one.