GEORGETOWN, Ohio -- Ohio Attorney General Mike DeWine says he didn't call the Romney campaign before endorsing Rick Santorum because "they haven't called me for months."

"I didn't think I owed them anything," DeWine told BuzzFeed tonight at a Lincoln Day Dinner event in Brown County that featured Santorum as a speaker. "They didn't have the courtesy to have the Governor even ever call me. Even after I endorsed him and called to say I was endorsing him."

"That's not bitter, that's not why I did this today," DeWine said. "I just went on with my business after that. But I don't think I owed them a call."

DeWine's flip to Santorum came as a complete surprise to the Romney campaign. A Republican strategist who spoke to a top Romney aide told BuzzFeed that even late this morning, the campaign wasn't aware of what DeWine had planned.

A spokesman for the Romney campaign didn't immediately respond to a request for comment.