Last night Diddy stopped by "SNL" with Dirty Money to perform on the Robert De Niro hosted episode.  See the performances inside plus get the deets on why two charities are saying the mogul ruined their fundraisers...

Swizz Beatz was a surprise guest on "SNL" as he joined Diddy and Dirty Money to perform "Ass on the Floor":

When they returned later in the show, Diddy and Dirty Money performed their latest song, "Coming Home."

And speaking of Diddy,

Two organizations are claiming their got stiffed out of monetary donations at a Diddy hosted party last month.  

The Long Island Plastic Surgical Group Foundation and 1 in 9: The Long Island Breast Cancer Action Coalition both say they were promised proceeds from  a "Pink Party" event for breast cancer, but their charities have received nothing.   Meanwhile, sources tell the NY Post that Diddy received nearly $80,000 for hosting the event. 

Held at the Glo nightclub in Westbury, Ny on Oct. 14, Carolyn Spector of The Long Island Plastic Surgical Group Foundation said "We never got a penny.  Nothing was written down, but we were told we would get part of the take.  The terminology was 'proceeds from the event. "

But that didn't happen as John Smythe, whose father, John Sr., owns Glo, sat the two charities at a table where they could ask for handouts. But then the charity reps ordered drinks and wandered off, John claimed.

"They were working a table for donations.  But they left the table later and start drinking. Seemed like they were into partying," he said. 

"That's just a bunch of crapola," Carolyn Spector fired back.    

"There was never any question of my setting up a table and trying to fund-raise on my own. That's not the way we operate. There weren't even chairs for us to sit down on. And I didn't have anything to drink."

Now the charities are upset because they feel stiffed out of donations while Diddy pocketed a five-figure fee. 

In response, Diddy told the NY Post he did nothing wrong and doesn't owe the charities a thing.

"I didn't know what the [club] owner promised -- that had nothing to do with me.  I had no information about the charity. When the event was booked, it was just for an appearance. I agreed to let him add the charity because I thought it was a good idea."

SMH.  Seems like Diddy isn't at fault and the charities want to blame a high-profile celeb for their bad business arrangement.  Shake them haters off Diddy.