Paris Hilton was spotted with mom Kathy at Lexington Social House only the day after Lindsay Lohan partied there with Emile Hirsch!

Maybe Paris had to see what all the buzz was about ... though she took to the spot at a calmer time of day than former pal Lindsay.

According to various online reports, Paris recently accompanied The Hangover director to Chateau Marmont, then was seen kissing him at Beacher's Madhouse at The Roosevelt Hotel in Hollywood.

So much for the not-wanting-a-new-man thing (Paris recently broke up with bf Cy Waits)!