Poll: Most surprising celeb split of the week? Michael C. Hall and Jennifer Carpenter? Scarjo and Ryan Reynolds? Zac Efron and Vanessa Hudgens?

In August, Michael C. Hall and Jennifer Carpenter arrive for the 62nd Primetime Emmy Awards in Los Angeles. (AP)

On what may henceforth be known as "Terrible Tuesday," we may just have lost our ability to believe in long-lasting celebrity coupledom.

First, "High School Musical" sweethearts Zac Efron and Vanessa Hudgens announced their break up after a relationship that saw them through the transition from teen idols to twenty-somethings.

Then, on the same day we learned that "Dexter's" Michael C. Hall had separated from his on-screen foster sister, Jennifer Carpenter amidst rumors of an alleged affair between Hall and another "Dexter" co-star, Julia Stiles. (Stiles denies any involvement, it should be noted.) Carpenter officially filed for divorce on Thursday.

But back to Tuesday. Before the day was out, GQ's Babe of the Year and People's Sexiest Man Alive -- Scarlett Johannsson and Ryan Reynolds -- announced an amicable split after just two years of marriage.