Last week MK went to see Good Charlotte perform at the Roseland Ballroom in New York City. A source tells Life & Style that Nicole's boyfriend Joel Madden invited the literary genius back to the tour bus for some hot baby action.

As in baby photos, not making.

"He showed her some baby photos of Harlow. Nicole freaked out."

Gosh, can you imagine? She probably let go of the stroller and sent it barreling toward a burrito stand.

"Nicole was hurt and angry. [Joel] couldn't deal with it, so he hung up, and she kept texting him after that."

Get over it, Nicole. Mary-Kate beat the feds. She can certainly have a lippy blonde disappear without a trace.