Another longstanding Hollywood couple bites the dust. After 14 years together, Pirates of the Caribbean actor Johnny Depp and French singer Vanessa Paradis have announced plans to separate. 

Although Depp denounced rumours earlier this year during a red carpet interview at the London premiere of "Dark Shadows," it seems the pair couldn't make it work. 

The couple has pleaded with media to respect their privacy, for the sake of their children: 13-year-old Lily-Rose, and 10-year-old Jack. This, on the back of another shocking celeb split questions whether long-term relationships can really work in Hollywood, and beyond. 

Even for non A-listers, the "overall probability of marriages ending in divorce falls between 40% and 50%," according to PolitiFact.com's analysis in February 2012. 

Moreover, and more depressingly, it's assumed that a great many of the couples that remain intact are doing so unhappily—for the sake of children or finances. 

Is marriage -- or monogamy, for that matter -- doomed? If so, why are we still rushing to the altar?