Charlie Sheen was busy on Father's Day tweeting on Twitter and writing an open letter targeted towards his ex-wife and mother to his two of his kids, Denise Richards. It appears the Anger Management star, could not see his kids that day for reasons unknown to us and is clearly blaming his ex-wife for this. "It started Sunday afternoon when Sheen reportedly began his rant tweeting, "Brooke M is a sexy rok star whom I adore D Richards a heretic washed up piglet Shame pile Happy Father's Day!!!" Denise seemed to be the victor in this one, when she tweeted back, "Happy Dad's Day! @CharlieSheen have a great trip in Mexico!" she tweeted. "Kids were disappointed u weren't here for it—Hey we'll celebrate when u r back!"