Jason Jones by Haidee Malkin/ WireImage.com Jason Jones by Haidee Malkin/ WireImage.com

Ex marks the spot for The Daily Show correspondent Jason Jones, who has been cast on CBS' How I Met Your Mother as Tony, Stella's onetime lover and the father of her daughter.

Sources tell TVGuide.com that Stella's ex appears on her and Ted's impromptu wedding day, perhaps throwing a wrench into the works. That would effectively derail the theory that Sarah Chalke's character is the titular momma.

Mother kicks off its new season Monday at 8:30 pm/ET. - Matt Mitovich

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