Backstreet Boy A.J. McLean and his new wife Rochelle DeAnna Karidis showed off their wedding rings -- and more importantly, their matching his & hers manicures -- at the Guns N' Roses concert in L.A. on Wednesday.

The couple that mani-pedis together, stays together.

He's getting married next week ... but Backstreet Boy A.J. McLean has blood on his mind -- sending out death-themed invitations that look like they were designed by Ed Hardy and Dracula ... and we got pics.

A.J. and his GF Rochelle Karidis are set to tie the knot on December 17 -- presuming all his guests aren't completely freaked out by the invites ... which contain bloody lettering and creepy gothic imagery.

The ceremony will take place at the Beverly Hills Hotel -- and celeb photographer Tyler Shields is officiating.

Don't get your hopes up for pics though -- according to the invites, all cell phones and cameras are banned.

The guys from the Backstreet Boys and New Kids on the Block hosted parties at Gallery Nightclub and Chateau Nightclub respectively last night -- after they played the Mandalay Bay Events Center.



What year is it again?

Backstreet Boy Brian Littrell claims there's one big difference between A.J. McLean's current stint in rehab and his last one -- no one FORCED him to get help this time.


Brian went on Bob 93.3 in North Carolina this morning, telling the host, "I'm proud that he would go into this situation willingly ... Last time it was a lot worse. He really went into rehab unwillingly the last time."

According to Brian, A.J. decided to commit to rehab over a month ago ... while the band was on the road.

A.J. McLean's issues with substance abuse have been the source of MAJOR problems in the past several months ... and it got so bad, that staffers on the Backstreet Boys' tour threatened to walk if he didn't get help.


TMZ has learned A.J. -- who's struggled with abuse for years -- was so hammered and rowdy on a BB fan cruise last month, that several passengers lodged complaints ... with some even demanding a refund. 

One cruise staffer tells us  A.J. and his crew acted like "drunken fools" for the entire five-day trip.

But after the cruise, the abuse continued ... and more people in his life threatened to jump ship.

Sources close to the singer tell us A.J. became so difficult to work with during rehearsals for the upcoming BB tour that multiple people were "ready to quit."

Fortunately, A.J. decided to check himself into rehab a few days ago -- but he insists he'll be ready to go for his upcoming tour.

A.J. McLean from the Backstreet Boys has gone into rehab again ... TMZ has learned.



One source tells TMZ McLean has been "out of control" in the last few months because of substance abuse, and it was interfering with plans for the Backstreet Boys' upcoming tour with New Kids on the Block.

Sources say on a Backstreet Boys cruise last month ... A.J. appeared under the influence much of the time.

McLean has battled addiction for years. He was in rehab in both 2001 and 2002 for alcohol and cocaine abuse.

McLean made a cryptic reference on his Twitter account, writing on January 9, "I love u all and wish me luck! I start my sober journey tomm!"

On January 10, McLean tweeted,  "See u on the other side!"

Video shot during a BSB cruise for fans last month shows McLean with what looks like a beer -- amber liquid with foam on top.



UPDATE: A.J. released a statement saying, "For personal reasons, I’ve checked myself into a rehab clinic. With 2011 being a busy year for Backstreet, I want to be healthy and perform & sing for people at my very best and happiest. None of this will affect our current tour plans and I look forward to seeing everyone really soon! Thank you for all of your support and respecting my family and friends privacy during this time."

Backstreet Boy AJ Mclean got his hands on a bottle of Jack Daniels, a costume from the "Halo" video game, and a butt-naked lady -- and posed up for one of the most random photo shoots we've ever seen.


It was all for a session with photographer Tyler Shields -- the guy who shot those semi-naked Lindsay Lohan "Inferno" pics.

AJ has been battling his issues with alcohol for years -- and we're guessing this whole thing was some sort of artistic interpretation of his inner struggle.

Either way -- NAKED CHICK!

Boy bands of yore New Kids on the Block and Backstreet Boys are joining forces to pay their bills go on tour together.



Question is ...

DJ Pauly D thinks he's got the right stuff for the upcoming New Kids on the Block/Backstreet Boys tour -- and now TMZ has learned he's "in talks" to be one of the opening acts.



Sources tell TMZ .... the "Jersey Shore" star is close to a deal -- but he's not the only act that's being considered. We're told Boys II Men is also in the running. 

Reps for the tour tell us, "[Pauly D] is one of many that has submitted himself to be on the tour. No opening act decisions are being made at this time."

A.J. McLean has a few theories about how he might have contracted pink eye -- and let's just say he hasn't ruled out Nick Carter as a suspect ...

The Backstreet Boys ain't afraid of a little contagious infection -- in fact, according to the band's rep, A.J. McLean's crusty pink eye won't have any effect whatsoever on the remainder of the band's tour.


BSB's rep tells TMZ, A.J. -- who was recently diagnosed with the leaky eye infection -- is "doing fine" ... and the band's current tour will go on as scheduled.

As for the other guys -- we're told the rest of the band was inspected by a doctor as soon as they discovered A.J.'s pus problem ... and they all tested negative.

No word on who farted on A.J.'s pillow.