"Dr. 90210" Robert Rey claims he was assaulted by a drunk dude in Brazil this weekend ... and the guy grabbed him by the nuts so hard the reality star says his testicles are STILL inflamed.

The doctor was dining at a restaurant Saturday in Campina Grande when he claims a man asked him to snap a pic. Rey obliged, but the man groped his crotch out of nowhere ... calling him "Dr. Gay."

Rey, who studies martial arts, says he defended himself by punching the guy twice in the jaw, and then took him down with a kick. His scrap with the guy sparked a drunken brawl between several other people in the restaurant, but Rey stayed out of it.

The reality doc says he didn't call cops and doesn't want to press charges because, "I was young and also did youth nonsense!"

Rey posted a picture of the nut job to prove he was justified in defending his family jewels.

William Shatner made a surprising return to Los Angeles Sunday ... but was quiet about whether he would attend Leonard Nimoy's funeral. 

Shatner tweeted on Saturday ... he would not be able to go due to a charity event he had scheduled in Florida -- however our photog shot Captain Kirk after his flight landed around 11:30 AM today. 

He remained tight lipped about whether a backlash from fans made him change his mind about paying his last respects to Spock. We reached out to his rep ... but so far no word back.

Shatner did talk to us about Terry W. Virts ... the astronaut who paid tribute to Spock by giving Earth a Vulcan salute from space.

2:50 PM PST -- Nimoy's rep says the funeral was at 9AM this morning ... which means Shatner was still in the air during the service.

Justin Bieber rang in his 21st birthday doing something common -- drinking champagne -- and something very few people can do ... popping that champagne ON A PRIVATE ISLAND! 

Sources close to Justin tell us he rented a Caribbean isle near Grenada for the "I'm finally legal" bash ... and based on this video, he had a great time celebrating with friends.

Bieber posted a pic on Shots of party ... and it looks like he's getting close again with model Yovanna Ventura -- who he was rumored to be hooking up with in the past.

Wonder if she came with a ribbon?

Dakota Johnson has joined ISIS ... well, at least a character she played on "Saturday Night Live"  -- and the Internet went CRAZY!

Check out the video ....Dakota's dropped off at the airport by her dad -- played by Taran Killam -- but instead of joining the army like the Toyota commercial ... she joins the infamously savage org.

Social media users blew up with anger ... with responses like:

- "I think it's safe to say I will never watch SNL or any of Dakota Johnson's movies ever again"

- "Dear #SNL, jokes about Isis are not funny. See how much you laugh when you have to see your loved one(s) being slaughtered. No respect."

- "Actually offended by the ISIS sketch... Is that seriously all you could come up with? @nbcsnl #SNL"

So we gotta ask ...

9:20 AM PST -- Taran Killam just defended the skit on Twitter saying, "Proud of this. Freedom to mock is our greatest weapon. Thanks to the writers who asked not to be mentioned by name."

Dave Matthews' handsome looks keep marching on.
 

Here's a 30-year-old version of the singer-songwriter and DMB frontman at an awards show back in 1997 (left) and 17 years later ... the now 48-year-old college dorm staple at an L.A. event last year (right).

"So much to say, so much to say."

Cops are flustered as to how the Lupita Nyong'o Oscar dress escaped detection when it was taken from her hotel room, but now we know ... it was thrown off her balcony. 

TMZ broke the story ... the surveillance video was unhelpful. The cameras weren't trained on Lupita's door and none of the cameras on the floor showed anything suspicious.

The guy who stole the dress -- who called TMZ Friday with a road map to recovery in The London West Hollywood bathroom -- told us he knew where the cameras were placed in the hallway so he was never seen. As for the dress ... he said he threw it over the balcony and someone on the ground picked it up. 

As we reported ... the thief says he took 2 of the pearls off of the dress and down to the Garment District for appraisal, but found they were worthless fakes. That's when the thief took the dress back to the hotel. 

The thief told us he knew Lupita was in the room where they took the dress and waited for the opportunity to enter ... which they did when they found the door was ajar. 

By the way ... the thief also says he saw Lupita's Oscar gift bag -- valued at $125,000 which he didn't take. Looks like he chose wrong.  

Gunshots rang out during a college event headlined by T.I. and Jeezy -- and the crowd scattered in chaos.

The rappers were playing at a day party in Charlotte when someone in the crowd fired what sounded like 2 shots. Police tell us two people suffered non-life threatening injuries ... and both were hospitalized.

Cops say no one's been arrested. They do not have a suspect yet.

Although a T.I. song was playing when the shots were fired ... we're told it was just a track -- T.I. had already performed and was not on stage. Jeezy and Yo Gotti -- who had also performed -- were in the V.I.P. section at the time of the shooting.

We've spoken to T.I.'s manager ... and he says T.I. wasn't hurt. We're also told Jeezy and Yo Gotti were uninjured.

The show was an event to celebrate the C.I.A.A. basketball tournament.

Jon Gosselin learned lesson #1 about show biz Saturday ... Everyone's gotta start somewhere.

That somewhere was a New Jersey bowling alley, where Jon made a guest appearance as a DJ.

The good news ... the one person who got up and danced really liked it.

Truth be told ... we spotted 2 others in the background at Brewster's Bar and Grill inside Laurel Lanes, where Jon put on a 5-hour set filled with every type of genre ... the musical equivalent of throwing darts.

Cindy Crawford's stock in trade is her body and now her people are out for blood, claiming the person who posted this pic (above) severely altered it to make her look bad.  

The lawyer for Cindy's photographer fired off a letter -- obtained by TMZ -- threatening everyone who posted the pic with a lawsuit if they didn't take it down and apologize. The lawyer says the original pic was stolen and then doctored to make her midsection look haggard.  

The lawyer included a statement from the famous photog, who says he took the pic for Marie Claire Mexico and someone stole it from him and Photoshopped it.  

The letter apparently worked ... some media outlets are already complying.

Shortly after the altered pic hit the Internet, Cindy's hubby, Rande Gerber, posted the pic below, showing the real deal.

Kevin Federline has gone from living in a $10 million house to DJing in the OC for a grand.

KFed will be spinning at Heat Nightclub March 7th. He's not making Britney money -- $475K a show in Vegas -- but he's getting a thousand bucks and that's a start. 

The good news ... he's still getting child support, although the $20K a month went down significantly after Britney stabilized and took more custody back. 

Here's the thing. Kevin is a happy guy who knows music and has even had a hit -- yes, "Popo Zao" counts. And we hear the club is pretty awesome and the crowd will go crazy if he plays it.

Kevin Federline. He comes tight with every rhyme. And he built a kingdom down the street from Pepperdine. 

Building Michael Bay's new mansion transformed a construction worker into an injured mess ... according to a new lawsuit filed by the guy.  

According to legal docs obtained by TMZ ... the worker says Bay didn't warn him about a dangerous hole on the property ... which was covered with plastic back in February 2013. In the suit, he says he tumbled through the opening, and was seriously injured. 

The worker isn't specific about his injuries in the lawsuit, but says he was hospitalized ... and paid out of pocket for his medical expenses. He also says he couldn't work while he was injured. He's suing to get reimbursed for his medical bills ... as well as damages. 

The mansion's been a long, slow, ordeal for the blockbuster director. He bought the property way back in 2009, demolished the home that was there, and eventually started construction on the new crib.

We reached out to Bay and his rep ... but so far, no word back. 

Even though this celebrity wasn't bourne with this face ... you might be able to look past the plumped pic to see the star underneath!