Real-life love triangles can be intense, including:

Rat Packers -- Humphrey Bogart, Lauren Bacall, Frank Sinatra: Few know that the original Rat Pack was actually started by these three. Questions remain whether Bacall and Sinatra's relationship started before Bogart died in 1957, but the survivors were engaged the next year. Not for long.

Icky triangle -- Mia Farrow, Woody Allen, Soon-Yi: The ultimate bizarre love triangle. Woody Allen was with Farrow for 12 years until he decided he liked her adopted daughter from another marriage better. It still sounds creepy.

Mr. and Mrs. Trouble -- Jennifer Aniston, Brad Pitt, Angelina Jolie: Jennifer Aniston and Brad Pitt were married until he made "Mr. and Mrs. Smith" with Angelina Jolie in 2005. He still is with Jolie.

The muse -- George Harrison, Pattie Boyd, Eric Clapton: George Harrison and Eric Clapton were friends whose relationship recovered after Clapton openly pined for Boyd in "Layla." He eventually got her. Then lost her.

The thief -- Debbie Reynolds, Eddie Fisher, Elizabeth Taylor: Eddie Fisher had the all-American marriage. Then Princess Leia's father dumped her mother for Elizabeth Taylor. Which, of course, didn't last long. Fisher eventually ended up with Connie Francis.

Attack of the Rottweiler -- Princess Diane, Prince Charles, Camilla Parker Bowles (aka The Rottweiler): Princess Diane once famously said in an interview "there were three of us" in her marriage, referring to Bowles, the woman she called the Rottweiler. Charles wanted Bowles, and got her in the end.

This had to hurt -- LeAnn Rimes, Eddie Cibrian and Brandi Glanville: LeAnn Rimes married backup dancer Dean Sheremet in 2002, which lasted until she had a much-photographed affair with Eddie Cibrian, her co-star in made-for-TV movie "Northern Lights" in 2009. Cibrian, married with two children, filed for divorce from Brandi Glanville that same year (Glanville did NOT take it well), while Rimes' divorce from Sheremet was finalized in 2010.

Can we still be friends? -- Heather Locklear, Richie Sambora, Denise Richards: When her marriage to Charlie Sheen feel apart, Denise Richards turned to pal Heather Locklear -- whose marriage to Richie Sambora was also crumbling -- for comfort. Then Richards stepped in and took the rocker for herself.

Don't mix work and pleasure -- Dennis Quaid, Meg Ryan, Russell Crowe: After a decade together, Ryan ditched Quaid for Russell Crowe while shooting "Proof of Life." The affair was short lived, but Quaid still filed for divorce two week after the mess went public.

Baby snatcher -- Joey Ramone, Linda Ramone, Johnny Ramone: Punk rock's most famous triangle started when guitarist Johnny Ramone stole singer Joey Ramone's girlfriend Linda. An ensuing brawl left Joey needing surgery for a blood clot in his head. The fiasco inspired Joey to write the song "The KKK Took My Baby Away." Though they continued to work together for decades in the Ramones, they rarely spoke.

Give her shelter -- Brian Jones, Anita Pallenberg, Keith Richards: While on vacation, Keith Richards stole bandmate Brian Jones' model girlfriend Anita Pallenberg, who Richards felt was being abused by Jones. Shortly after, Jones was kicked out of the Rolling Stones and died only weeks later by drowning in his pool. While with Richards, Pallenberg also had a fling with Mick Jagger, though she remained with Richards for a decade or so.