Ashlee Simpson and her new reported beau, Evan Ross turned up the heat and rumors about their budding romance.

Word is that Simpson, 28, and Ross, 24, spent the Fourth of July together at Guy Oseary's star-studded party hosted by Deleon Tequila at Nobu Malibu, according to US Weekly. Witnesses said they looked quite comfortable, whispering in each other's ear and sitting close. With such an intimate demeanor, they looked like a lot more than friends.

[For our first story on the alleged couple getting cozy, click HERE.]

There were more sparks flying between the twosome than in the actual fireworks show. The pair, whom cameras caught together on Monday and Tuesday, arrived at the big holiday bash with a group of friends, but soon cozied up together. "They were all drinking and enjoying the music," a source said. "Ashlee and Evan chatted intimately, whispering in each other's ears and making each other laugh."

And things also got quite steamy. At one point, Ross, son of the legendary Diana Ross, "put his hands on Simpson's thighs and sat very close to her. He basically focused his attention only on her," the source added.

Noticing the magnetic pull between the two, they "definitely looked like more than friends," said a second insider.

Another witness noted they were " totally lovey dovey and holding hands." Though a slew of celebrities from Mel Gibson, Charlize Theron and Woody Harrelson joined them at the soiree, it looked like the two only had eyes for each other.

But, earlier this week, US reported that the twosome were just very close friends. "Evan and Ashlee have been friends for a really long time, probably 10 years," a source said of the duo. "They know each other from the club scene and have tons of mutual friends."

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