So, I work with someone who I tolerate as they are a true narcissist. They were immensely overweight, managed to lose a large amount but weight is piling back on. Its hard to watch the entire company talking about them behind their back about their clothes smelling dirty (like they've been worn all week), feet smelling even with shoes on, but worst of all, their teeth... They are completely caked in the thickest tartar I've ever seen and their breath literally smells like they've been eating poop. It's so bad that at 8 feet away, it makes me gag. Its become the laughing point of people who dont even know them that people have numerous awful nicknames for them. How do I approach someone who refuses to think anything about them is wrong, and thinks you are jealous or you are a bully if you criticise or give gentle advice!