Mia Farrow may have revealed a little too much of her lingering feelings toward ex Woody Allen on Twitter last night. After “Half the Sky” co-creator Nicholas Kristof tweeted, “Now there are apps to deal with a messy break-up, by eradicating an ex online,” Farrow — humiliated when Allen took up with their adopted daughter Soon-Yi — retweeted, “Wow! Am I too late?” She later thought better of it and deleted the posting, but not before it was retweeted by others.