Paris & Stavros' Miami Hookup?

According to a report — and some incriminating pics — on Bloggarazzi.com, there might be trouble in paradise for celebutant Paris Hilton and boyfriend Benji Madden, after the hotel heiress was spied getting cozy with her former beau, hunky Greek shipping heir Stavros Niarchos!

The item claims that Paris and Stavros were together during the entire evening of the 2008 Victoria's Secret Fashion Show, including the late-night after party at local hotspot Mokai, where the pair were "flirting and kissing." So we did some digging of our own and came up with the dirt:

"They slipped in secretly together holding hands very, very early in the morning," an eyewitness tells OK!. "They were cuddling and whispering together all night. Stavros was making Paris laugh — She couldn't stop smiling when he was around and they were dancing together very closely."

CLICK HERE for OK!'s Ultimate Paris Gallery!

Continues the fellow partygoer, "They looked like they were back to their old ways and you never would have thought she had a boyfriend. She was all about Stavros. They left together and went back to their hotel."

Meanwhile, Paris' rocker boyfriend Benji spent part of his weekend in NYC, where he and brother Joel Madden put in an appearance at Sunday night's live finale of MTV's Total Request Live.