facegag
a feeling of dread or disgust at seeing that two of your Facebook "friends" who have no reason to know one another have become friends with each other on Facebook, likely as the result of online flirting or a sexual encounter.
While looking through my Facebook news feed, I had to facegag when I noticed that my ex was now Facebook friends with the the town slut... who just happens to live in a town 2000 miles away that my ex recently visited.