Ashlee Simpson is about to get married this weekend to Evan Ross, and it looks like the couple celebrated another big day as they prepare to start their lives together.

Ashlee Simpson Modeling Chatter

The younger sister of pop star Jessica Simpson reportedly celebrated her fiance's birthday this week that consisted of a special evening, according to Friday's report from Hollywood Life.

"On August 26, the queen of Motown, Diana Ross, was seen with her entire brood at SYK Downtown [in NYC] to celebrate her son Evan Ross' 25th birthday and his upcoming nuptials to singer Ashlee Simpson this Labor Day weekend," a source told the site.

Ashlee Simpson, Evan Ross Dating Chatter

Ross's birthday dinner apparently included of a lot of delicious courses as well as flirting and some details about the day he'll tie the knot with Simpson.

"The large group of 16 was...in great spirits, eating lobsters and filets, while sipping on Macallan & cokes," the source said. "There was lots of wedding chatter overheard from the group and tons of PDA from Ashlee and Evan who are reported to be tying the knot at Diana's Greenwich Connecticut estate this weekend."

The site also mentioned that Simpson, who was also known as a young pop sensation, even spent time with her future husband before the dinner took place.

"Ashlee and Evan were spotted earlier in the day at Bowlmor Chelsea Piers, celebrating his birthday with friends and family," the insider said.

Fans might be interested to come to the realization that Simpson's future mother-in-law is going to be Diana Ross, one of the biggest music icons of all time.

Tags: Ashlee Simpson Evan ROss