Have you ever met 2 people that were so similar in mannerisms and sense of humor that it was scary? It's even worse that they know it and feed off of each other.
Meet Ken and Eric. They meet the above description.
When told to do something funny, they both grab their ties. One day they dressed exactly the same. Marsha said it was excruciating. We told them they didn't really look alike and Eric replied, 'Exept for the fact they are both VERY good looking. Hmmm (Say it the way Nanny McPhee does.)