I was sitting in my cubicle this morning. There are three other desks in my office, and an open area between two of them. My manager came in and was chatting about non-work stuff with those two coworkers. All of these people know of my involvement with local animal anti-cruelty organizations. I was separated from the conversation by a cubicle wall.
They started discussing living on farms, and then went on to discuss pets vs cats on farms and how feral farm cats overbred and became pests, and violent ways of how to deal with having too many. Then they discussed cats and their tendencies to get into car engines in the winter, there was also a comment by one of them on how funny it was that their farm dogs chased the cats.
I was sitting there silently horrified. I didn't know what to say that would not make me look bad in front of my manager, yet keep them from discussing that kind of stuff in front of me.
Later when I was invited to coffee with them I had to bite my tongue to avoid saying "No thanks, I've had enough discussion of animal cruelty today".
What to say?
Are you allowed to wear headphones? Because I would put those on.
I think if you say anything, it's going to get touchy. Everyone but you was okay with the conversation (even if it was wrong), so you would be seen as being "sensitive", especially considering the nature of the conversation and your diametrically opposing viewpoints. There's nothing wrong with being blunt, but if you want to avoid icky office wars you could:
Say you're on the phone, please quiet down.
Say you can't concentrate, could they move their conversation?
Put on headphones.
Say you're trying to eat and the convo is ruining your appetite.
Um, guys? The wall here isn't doing much to block your conversation. Can you move it somewhere? I need to be at my desk and I'm having a little trouble concentrating.