“Why should bread have all the fun, when there’s Weetabix?” Asked Weetabix’s official Twitter account. “Serving up @HeinzUK Beanz on bix for breakfast with a twist. #ItHasToBeHeinz #HaveYouHadYourWeetabix” They said, accompanied by a provocative image of baked beans slathered on top of the nation’s favourite cereal bricks. Such a tweet would have been obnoxious and…