The duo broke things off again Monday night after a nasty argument. One major point of friction between the two was Sam's friendship with Nicole Richie, who's apparently no fan of Lohan.
"Nicole refuses even to be in the same room as Lindsay," says a source, noting that just last week Nicole invited Sam to a mutual friend's birthday party at Bar Marmont with the stipulation that she not bring Lindsay. "Sam went to the party, and it really upset Lindsay," says the source.
After Sam had dinner with Nicole at Izakaya last night, a source says she gave Linds the kiss-off.
Sam's rep declined to comment on her personal life, and Richie's rep could not be reached for comment.