There was a film I vaguely recall from my childhood, so late 80s early 90s. There were two single parents and one (or both?) had a awfully behaved child, one girl and a boy. I remember a scene where there were a lot of bugs crawling into a bedroom as a prank. There was also some misbehaving in a restaurant, possibly in the toilets. I think the kids were tying to prevent their parents getting together. Somewhere near the end was something to do with the Blarney Stone. One of them kissed or touched it and made a wish (maybe), and then I think the couple got together. Any ideas?! Thanks