Lindsay Lohan and rumored lover Samantha Ronson headed to Chicago on April 24th , for DJ Samantha's gig at the Crimson Lounge, inside the Hotel Sax.

LINDSAY LOHAN on her best behavior?

"Samantha is the resident DJ at the lounge, and comes in once a month," a source tells Star. "This time, Lindsay came with her and spent most of the night next to her inside the DJ booth."

"Lindsay was on her best behavior," says the source.

After Samantha's Chicago show ended at 2 a.m., adds the source, she and Lindsay retired to their shared $600-per-night Signature Suite at the hotel, before flying out the next day.

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