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Ashlee Simpson's Engaged! Other Celebrity Quickie Engagements
PHOTO: Ashlee Simpson and Evan Ross arrive at the Los Angeles Premiere The Hunger Games: Catching Fire at Nokia Theatre L.A. Live on Nov. 18, 2013 in Los Angeles, Calif.

On Monday night, Ashlee Simpson, younger sister of Jessica Simpson, announced that she and music icon Diana Ross' son Evan are engaged.

"My baby love and I are ENGAGED!!!" she posted on Twitter.

The 29-year-old actress and singer has only been seeing Ross for a few months. The two were first spotted as a couple in July, but it already seemed serious, because they went out twice in 24 hours, including a late night at Teddy's, the club at Hollywood's Roosevelt Hotel.

But Simpson isn't the only celebrity to get engaged after such a short period of time. Here are some other happy couples who just knew after only a few months.

Avril Lavigne and Chad Kroeger

The duo began working together in March 2012 on Lavigne's fifth album and things heated up quickly. By August 2012, they were announcing their engagement! That's less than six months of dating.

Things seemed to have work out for Lavinge, 29, and the Nickelback frontman. Their song "Let Me Go," came out in October after they were married in the South of France on July 1.

Kaley Cuoco and Ryan Sweeting

The "Big Bang Theory" star, 28, got engaged to the tennis pro in September of last year.

The couple had only been dating for a few months, but, a source told US Magazine that the actress, 27, is smitten. "When you know, you know," the source said. "[She has] never felt this way. She knows this is it. And the ring is gorgeous!"

The two were married on New Year's Eve 2013.

Kate Hudson and Matt Bellamy

The "Something Borrowed" actress, 34, became engaged in April 2011 after the couple already announced in January they were expecting a baby.

Bellamy, lead singer for the band Muse, dated Hudson for less than a year before he knew he had to put a ring on it.

Hudson, who now has a two-year-old son Bingham Hawn with Bellamy, said of the quick engagement, "It was very sweet. It was very romantic."

John Krasinski and Emily Blunt

It took just nine months for "The Office" star, 34, to know Blunt, 30, was the one. The now-expecting couple were engaged in August of 2009 and married on July 10 in Italy.

"I was like, I'm going to propose to her real fast before she wakes and was like, 'What am I doing? I can have anybody,'" Krasinski told People magazine in 2011.

The happy couple is expecting their first baby in a matter of days.

Jessica Simpson and Eric Johnson

Last but not least is Ashlee's sister Jessica Simpson, 33, who announced her engagement in 2010 to NFL star Eric Johnson after only six month of dating.

The two have yet to tie the knot, but have two beautiful children - Maxwell, 20 months, and Ace Knute, 6 months.

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