Eastwood, the E! reality-television star was celebrating her birthday on Tuesday when Lindsay Lohan made her grand entrance.
One source told Us Weekly: "Francesca was celebrating her birthday with around a dozen friends in a private area when Lindsay came over and started screaming that Francesca should leave. She was yelling 'I'm a star, she's a nobody, get her out of here!' One poor guy came over and tried to calm [Lohan] down and she acted aggressively."
It eventually got so uncomfortable that security personnel had to step in. "[I]t was totally embarrassing," the source said. "She is acting like some bad '80s film star, and it is hard to watch because she needs help."
When LiLo finally made her exit, a witness told Us Weekly, "Lindsay's friend was driving and they sped out and almost hit one of the valet guys."
Eastwood told E! News, "I'm not sure what exactly sparked Lindsay's outburst."
However, Lohan used to date Eastwood's boyfriend Tyler Shields, according to E! News, which could have prompted Lohan to crash the party.
"We were celebrating my girlfriend Francesca's birthday at Bootsy Bellows, and it was a blast," Shields told E! News. "Suddenly, there was a burst of chaos, and as quickly as it started, it was over. After the fact, we were all a bit confused about what just happened."
Just a week ago, it was rumored that Lohan and Stewart had become chummy and were hanging out at a beach party in Orange County, according to celebrity blogger Perez Hilton.
It's been said that Lohan's brother was in Orange County for a pro-surfing event, which would account for Lohan being in the Orange County area.
Could "LiLo" and Stewart turn out to be true best friends forever? It's not that far of a stretch. Lohan needs a high-profile Hollywood friend, and Stewart could certainly use a friend after the Sanders/Pattinson debacle, even if it's Lindsay Lohan.