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Whenever talk of trouble begins for Justin Timberlake and Jessica Biel, it's almost always followed by a show of togetherness. Which means we can probably expect an affectionate couples outing sometime soon now that shots have surfaced of the crooner in the vicinity of a scantily clad, fishnet-sporting dancer at a Las Vegas club.

Cautious, paparazzi-savvy type that he is, Timberlake kept his hands firmly in his pockets while chatting with the shapely brunette, who Radar Online claims was one of several "hot girls" orbiting around him as he partied with his buddies at hot spot Tao into the wee hours of Thursday morning.

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Later on (and we urge you to take this next part with a big boulder of salt), the party supposedly moved to Justin's suite, although it seems the invite may have been BYOB, because Radar says two dancers showed up with a "giant bottle" of champagne.

Where was Jessica during her beau's jaunt to Sin City, which he made in part to promote his new 901 Silver Tequila brand?

She was in New York for the premiere of the documentary, "Summit on the Summit," which centers on the recent Mount Kilimanjaro climb she took part in to raise awareness for the global need for clean water. Timberlake provided an introduction for the doc.

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On the red carpet, the plush-lipped actress laughed off rumors that she was upset about Justin sharing a love scene with ex-girlfriend Cameron Diaz in the currently shooting flick "Bad Teacher."

"I haven't read the script, but I think it sounds fantastic," she enthused to E! News of their hotel-set close encounter, which, according to Life & Style, ends with Cam's character complaining, "That was fast." "It sounds like it will be so funny. Obviously, I'm super-excited for him."

Also feeling excited is the pair's pal and personal trainer, Jason Walsh, who tells E! of their coupling, "There's confidence in the relationship and respect and honesty and communication. It's rare in this world -- and especially in Hollywood -- that you see that and it's kind of beautiful. I respect that a lot."

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This week's In Touch contends that Biel was "floored" and "fuming" when Timberlake decided to co-star with his former flame but is "trying to pretend it's not a big deal."

Not so, a source tells Gossip Cop, insisting that "nothing could be further from the truth."

Besides, a set insider assures Hollywood Life that Cameron and Justin have been "strictly professional."

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