Few people know how to make a good time even better like Jim Carrey. I have no evidence for this belief beyond his generally wacky behavior, but he seems like the sort that is good at lightening the mood, even when it’s already pretty light. Jim and girlfriend Jenny McCarthy are currently in Park City, Utah for the Sundance Film Festival. In fact most of Hollywood has cleared out entirely, if I’m to believe the majority of the Sundance-related reports I’m reading.

Jim turned 47 on Saturday, and is still looking damn fine. In that goofy/hot way. And to celebrate, he went for some good old fashioned bumping and grinding onstage with G-Unit member Lloyd Banks.

Rapper 50 Cent ensured Jim Carrey’s 47th birthday was an event to remember by inviting him to join his G-Unit entourage onstage during a live performance. The Yes Man actor celebrated his big day by catching the rapper’s performance at Sundance Film Festival’s Vitaminwater house in Park City, Utah, on Saturday.

The birthday boy, along with his actress girlfriend Jenny McCarthy, headed directly for the balcony where the star was performing with his hip-hop group G-Unit, reports the New York Daily News. A source tells the newspaper, “Jim and Jenny were dancing and really getting into the music, so 50 decided to bring him out to the balcony for a special rendition of In Da Club (which repeats the line “It’s your birthday”).

“When Fiddy told the crowd, ‘I have a very special guest for you’, everyone was floored because he had just done a duet with Robin Thicke. They thought the surprises were over. Then 50 started singing and Jim appeared, and the crowd just lost it.”

Carrey didn’t show off his rapping skills – but he did win laughs after lip-syncing along with 50 Cent and showing off his hip-hop dance moves. The witness adds: “Jim was bumping and grinding with (G-Unit member) Lloyd Banks. It was pandemonium in the best way.”

[From Starpulse]

Now this is how you do a birthday properly. There’s no need for the stereotypical cake and ice cream when you can shake it on stage with another dude. And who in the world would want to dance with Jenny McCarthy anyway? Blech. It sounds like Jim had a good birthday that was certainly in keeping with his love of fun.

He is in town promoting his film, “I Love You Phillip Morris.” When asked by an audience member what it was like to kiss Ewan McGregor, he responded, “‘A dream come true!’ … ‘I mean, look at the guy!’” There were no reports of Jim kissing anyone in G-Unit, but Sundance isn’t over yet.

Here are Jim and Jenny at Sundance today and over the weekend. Images thanks to WENN and Splash.