Hook Ups

Joan Rivers' only daughter Melissa has been meeting with the king of celebrity sex tapes Steven Hirsch ... but it ain't to star in a XXX flick, TMZ has learned the two are actually dating.

Sources close to the couple tell us Melissa -- who runs "Fashion Police" on E! -- has been dating the Vivid Entertainment honcho for a couple of weeks ... after meeting through mutual friends.

One person with direct knowledge of the situation tells us, "The relationship is going great."

Now that his marriage to Ashlee Simpson is officially over ... Pete Wentz hit the town with his NEW model girlfriend Meagan Camper in L.A. last night.

UFC face-smasher Dan Henderson had TWO babes on his arm as he left a Hollywood nightclub Monday ... but one of the chicks MAY have been a rebound for one of the best pitchers in baseball.

Henderson -- who recently beat Shogun Rua in one of the greatest MMA fights ever -- hit Playhouse last night with Detroit Tigers pitcher Brad Penny.

But when they left, Penny went to the car by himself ... and Henderson followed behind with 2 chicks on his arm.

Here's the rub -- Penny is rumored to have called off his engagement to "Dancing with the Stars" pro Karina Smirnoff recently ... so is it possible Dan was helping his famous pal rebound???

Or was Henderson hoping to ride the tricycle by himself last night?

Ryan Reynolds and Blake Lively shacked up together at a bed and breakfast in Utah the other day ... AND TOTALLY MADE OUT!!!

It all went down over Thanksgiving weekend ... saliva was exchanged, embraces were shared ... and they probably banged the hell out of each other.

Jennifer Lopez's 24-year-old backup dancer boyfriend Casper Smart is still living the high life -- hitching a private jet with his Latin cougar to fly from L.A. to Morocco this week.

Casper and his sugar mama of two are set to perform at a Moroccan mall -- but before they got down to business, they were spotted having a romantic dinner at a place called Rick's Cafe in Casablanca.

Jennifer Lopez's lips say she's moved on to new BF/dancer Casper Smart -- but at least one of her fingers seems to be holding on to her ex.

While J.Lo snuck a few cougar kisses with Casper between rehearsals in L.A. ... she was still sporting what looks a lot like the 8.2 carat wedding ring she got from Marc Anthony.

Sara Gilbert is one helluva rebounder -- the former "Roseanne" star/ "The Talk" co-host was holding hands with 4 Non Blondes singer Linda Perry this weekend ... just a few months after splitting with her partner of ten years.

No word if the two are "official" yet -- but they definitely seemed couplish as they strolled around West Hollywood together.

For the record -- Perry ain't no one hit wonder ... she's super successful in the music world, having written and produced songs for everyone from Christina Aguilera to Pink.

Gilbert has two children with her ex.

Paris Hilton spent some quality time spinning on the water on Jet Skis with her new man friend, Grammy-winning producer/DJ AfroJack in Hawaii yesterday.

Looks like these two will be making beautiful music together.

Prince Harry was full on FLIRTING with a super hot waitress at a Las Vegas nightclub Sunday night ... and TMZ has the footage to prove it.

No word on the identity of the scorchin' brunette -- but sources inside XS nightclub at the Wynn Hotel tell us she was VERY LUCKY to get that close to the Prince, because dude was rollin' with an ARMY of security.

What happens in Vegas ... could get this chick into Buckingham Palace if she handles it right.

After attending a Halloween party together on Monday night, rumored lovebirds Wilmer Valderrama and Demi Lovato were seen sucking face outside Wilmer's house on Tuesday.

The couple previously dated back in 2010, after Demi split from Joe Jonas.

Marc Anthony doesn't need J.Lo to have a good time ... 'cause dude seemed to be having a blast in Costa Rica this week while some chick planted a big, fat kiss on his cheek.

Anthony -- who separated from his baby mama back in July -- threw a HUGE party a few days ago to launch his new TV show ... a Latin singing competition called "¡Q’Viva! The Chosen," which is set to debut in early 2012.

We're told Marc got behind the DJ booth for a while a spun a couple of records -- and later took a couple of cozy pictures with a woman named Dianna Perez, who's part of the crew.

"Family Guy" got it all wrong -- it's been 15 years since "Jerry Maguire," but ex-child actor Jonathan Lipnicki's still got the magic touch ... pulling seriously hot tail in Vegas last weekend for his 21st birthday.

You may recall -- "Family Guy" blasted Lipnicki in an episode last year, implying the once-adorable child actor had grown up into something ... less than attractive.

But that just ain't true ... because according to sources at XS Nightclub in Vegas -- where Jonathan celebrated his 21st on Saturday -- the actor had absolutely no trouble attracting several fine females. (exhibit a, above).

Newlyweds Robin Williams and his third wife Susan Schneider enjoyed a public display of face sucking while on their honeymoon in Paris on Tuesday.

Selena Gomez & Justin Bieber went to a Winnipeg Jets game this weekend ... but the only hockey they were interested in was of the tonsil variety.

Possibly dating former co-stars Blake Lively and Ryan Reynolds were spotted this morning outside Ryan's apartment in Boston, MA.

Wearing his and hers shades, "Real Housewives of Beverly Hills" widow Taylor Armstrong enjoyed a friendly lunch with "Most Eligible Dallas" hunk Matt Nordgren at Clementine Cafe in L.A. on Thursday.

While the Bravo stars have been rumored to be hooking up, Nordgren is adamant they are just "friends" ... and Armstrong just tweeted "I am NOT dating anyone from anywhere! Stop the rumors! I am trying to heal with my daughter."