Trouble in Paradise for Lindsay & Sam?

It's always tense when you meet your significant other's family — perhaps that's why rumors are coming out of Miami that there was a spat last night between Lindsay Lohan and gal pal Samantha Ronson.

Witnesses outside the Delano Hotel, where the Georgia Rule star  — and almost a dozen of Sam's family — is staying, say that all was not well between Linds and her constant companion when they returned home after a night of dining at The Shore Club's Nobu restaurant.

But if the pair did get into a spat, it wasn't over dinner. Sources inside the restaurant while Sam and Lindsay dined tell OK! that everything looked fine between them.