Talk about a bad reaction.
On her first trip with her sons back to Louisiana since she lost custody, Britney Spears' youngest son, Jayden James Federline, was rushed to the hospital for having what Spears' reps deemed a "reaction to something he ingested."
Although the 2-year-old tyke has since been released and declared "fine," it's possible an even worse reaction could transpire, should Kevin Federline seek to restrict Spears' remaining custody rights for the duo's two sons.
"If she was negligent - for example, he couldn't eats nuts or shrimp and she fed him that - then Kevin could go in and get an order modifying custody," L.A.-based family law attorney Lynn Soodik tells E! News.
There was no immediate comment from Federline's attorney, Mark Vincent Kaplan, about whether he will seek any restrictions, but Soodik suggests Federline might have several options.
"Perhaps they'll put a monitor back in, or maybe it might even be the children can't be with her without the father around," Soodik continues. "But then they have to show that she really put them at risk."
Whether it was food or prescription medication, Soodik says it will really come down to whether Spears knew her son had an allergy and if she was negligent by leaving something out that he could get into:
"I would assume if it's something he's allergic to that nobody knew or a reaction that any child could have, no one is going to do anything, because it's something that could happen to anyone."
If she did know, however, it could spell some much-unneeded trouble for the pop star.
"She'll have to pay the piper."
UPDATE: Longtime Kevin Federline attorney Mark Vincent Kaplan exclusively tells E! News that, as far as he knows, 2-year-old Jayden James' emergency trip to the hospital was most likely the result of a food allergy - and Federline, who was immediately notified of the incident, has no plans "as of now" to seek an explanation from his ex in court.