Report Offensive Message

I've been in this type of position and worse, my neighbor was nosy as well, so he would pass by my desk and try to see what was on my screen! Why? I have no idea, it was work for pity's sake. Finally I had to get over my upbringing and be rude, but I did it in a polite way. I told him to pipe down when I need some silence. I started this when I was on the phone, I always followed it my thanking him when he did and apologized for having to be rude. At worst he wasn't going to like me anymore and think I was a really rude person. YAY!!!!! He never really stopped, but he was the one apologizing when I had to remind him.