I occasionally enjoy making people uncomfortable.
This is a shared personality trait between us, then. Being anti-social I enjoy being sardonic as much as possible, and when I get the chance I also enjoy crashing conversations between others.
Example: some acquaintances of mine were once discussing their favorite carbonated beverages with one another. At one point I interjected and announced the fact that I rarely drink soda but instead indulge myself with milk as much as possible.
The only thing they had to say in response was, "Well, that's healthy..."
It was a calculated trade-off. True, from then on I appeared only to be a dork in their eyes, but so what? I had destroyed their friendly exchange forever. >:-)