In what has to be the strangest celebrity pairing in the world -- not to mention the most surprising -- Ashlee Simpson, erstwhile pop star & sister of Jessica Simpson, has announced that she is engaged to Evan Ross, son of legendary pop diva Diana Ross.

According to E! News, the pair -- who didn't really give too much of an indication that they were dating in the beginning -- got engaged during a vacation in Hawaii. And, of course, like most celebrities are wont to do these days, she announced it on Twitter. "My baby love and I are ENGAGED!!! Hallelujah Hawaii !!!!!" Ashlee tweeted this afternoon. (The nod to the Supremes song "Baby Love," sung by Evan's mom, Diana Ross, did not go unnoticed.)

Further, according to The New York Daily News, this is not the first time that Simpson has been married (though it is the first time for Ross's son, Evan, who has been plagued with gay rumors since he first entered the public eye). Previously, she was married to Fall Out Boy's Pete Wentz, with whom she has a five year old son, Bronx. "Ross has boldly declared that the 'Pieces of Me' singer is 'the one' for him. 'I'm so in love, and we've got amazing things going on,' he told The Daily News at the 'Hunger Games: Catching Fire' premiere in November. 'We inspire each other,'" the News reports.

Ross will next be seen in the movie, The Hunger Games: Mockingjay, which is the sequel to the hit movie, The Hunger Games. "Simpson told E! News in November that she was 'really happy' with Ross, and then he told us at the Hunger Games: Catching Fire premiere that he was bringing his girlfriend and her son home to his mom's house for Christmas. Ross will be playing Messalla in Mockingjay Part 1 and Part 2, and Simpson gushed to E! last month that she was 'so excited' for him," reports E! News.

Congratulations to the happy couple!