By Lily Rose

It’s 2.6 inches wide and 6.1 inches long, and we all want it.  We’re not sure what you’re thinking, but we’re talking about the Benjamin’s, dough, loot, c-notes, otherwise known as … money. The green stuff may not be the root of all evil, but it certainly is the root of a lot of relationship woes. Just ask these celebrity couples:

1. Sir Paul McCartney and Heather Mills: In June 2002, model Heather Mills and former Beatles member, Sir Paul McCartney, married, but then divorced just four years later. Money may not have ruined this couple’s marriage, but it certainly made an amicable post break-up relationship seem improbable. Once the divorce papers were filed, the mudslinging started. Mills branded McCartney an abusive drug user, while she was labeled as a high-class prostitute. Watching the nasty insults and allegations flying back and forth was like watching a fast moving tennis match–it left the public dizzy and a bit nauseous. With a model on one side of the court and music royalty in the other, our bets were on McCartney. Mills ended up with a £24.3 million settlement, a mere fraction of McCartney’s total net worth.

2. Rihanna and Chris Brown:  It’s all in the tweets, folks. Pop star Rihanna and long time ex-beau, singer Chris Brown, may be doing a little something-something on the down low. Brown’s new girlfriend, aspiring model, Karrueche Tran, and Rihanna have even engaged in a little social media sparring on Twitter. If Rihanna and Brown are privately seeing each other, money is a likely factor in their unwillingness to publicize their reconciliation, as Rihanna fans may never forgive the pop princess for taking back her abusive ex. And seeing Rihanna and Brown together is just one more reminder of Brown’s assault conviction— a reminder his career may not survive.

Related: Rihanna Explains Why She’s Still in Contact with Chris Brown

3. Nick Lachey and Jessica Simpson: No one can argue that reality television is financially lucrative. But, many celebrity couples pay the ultimate price — their relationship. Just ask Jon and Kate Gosselin, Travis Barker and Shanna Moakler or Carmen Electra and David Navarro. Maybe it’s the stress of having each of your private moments taped and shared with the public, or maybe it’s having a camera crew following you around, hoping for controversy. Who knows? But one thing is crystal clear — couple-centered reality TV shows are almost always a precursor for divorce. For singer Nick Lachey and Fashion Star judge, Jessica Simpson, however, divorce may not have been such a bad thing. On July 15, 2011, Lachey married television host, Vanessa Minnillo and on May 1, 2012, Simpson and fiancée, Eric Johnson welcomed their daughter, Maxwell.

Related: What Attracts Us to Bad Boys?

What are some other celebrity couples who let money get in the way? Share your ideas below.