My husband does not like cinnamon - not the taste, not the smell, nothing. He can detect the smell in our house hours after I used it (yes, I keep it in the house and will cook with it occasionally, as I enjoy it). Did you know that Oriental 5-spice includes cinnamon? Well, I know now...
He was not always very willing to try new foods until we got married, and he is getting better, but he just cannot eat anything with cinnamon. He isn't rude, he just turns it down. And when he does this, I've noticed that he'll go almost overboard complimenting the other food and appreciating other foods being served.
We were at a friends for lunch one day and they made a big deal about the dessert - a chocolate brownie pie thing. Well, turns out it had 1/8 of a teaspoon of cinnamon in it and they made a big deal about how he ate it and it didn't kill him, etc, etc, etc.
This was a few years ago, and I'm still upset about this.