After nearly a month of endless speculation, Ashlee Simpson and Evan Ross finally went public with their budding romance at a New York City event on Tuesday, according to US Weekly. 

Diana Ross' son, 24, came out to support the "Chicago" Broadway Star, 28, at her big sister Jessica Simpson's Fall 2013 campaign launch at Above Allen, reported US.

The twosome were walking hand-in-hand, and happily posed for a rooftop shot in front of the city's alluring skyline. They looked very lovey-dovey, with Simpson rocking a long flowing turquoise frock while her new beau was the definition of handsome in a stylish grey suit jacket over a printed v-neck shirt. 

This was the latest in several sightings of the longtime friends turned lovers. On July 1, cameras caught Ross and Simpson leaving Teddy's Nightclub at the Roosevelt Hotel in Hollywood, sparking dating rumors. 

Ross and Simpson, who is mom to 4-year-old son, Bronx with ex-husband, Pete Wentz, were also caught grabbing lunch together in West Hollywood a day after on July 2, reported US.

A source said that they had become very close before falling for each other.

"Evan and Ashlee have been friends for a really long time, probably ten years," the source said. "They know each other from the club scene and have tons of mutual friends."

And now, they have officially taken their relationship to the next level in letting the world in on their romance. A source close to Simpson said that the couple are very in-sync with each other, "It helps that they were friends first."

"They have a long bond," the insider continued. "They already know each other really well."

Just a day before their first public appearance as an official couple, Ross and Simpson arrived at LAX Airport in Los Angeles and held hands before boarding a departing flight, according to JustJared. 

For airport photos of the couple, click HERE.

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