I am an atheist and I have only really told my immediate family. This is mainly because my sister is an atheist to so we talk about it pretty openly in my house. However, when it comes to social situations and religion is brought it can get a little awkward. Most the time people will ask if I am Catholic or Christian and I normally just say no and leave it at that. How would you tell people that you are an atheist?
I like what you mean. I just straight out tell them, you know what? You need to mind your own business. That or you can say, look im an atheist if you ostrasize me that's your problem or say look i have no religion, i dont care if you do just dont bug me about it. I HOPE THAT HELPS YOU EMMA!
I did get stymied once when getting signed up at a hospital. They asked what religion I was. Took minutes before I thought to ask if I needed a religion to get treated. Which flabbergasted the receptionist.