@plainoldme,
That was the father of the bride, giving her away. The serialized story on BBC had a very complicated plot. The father of the bride is the owner of some small-time casino in Blackpool, England. David Morrissey is the actor playing the casino owner. David Tennant plays a police detective investigating the activities of the casino owner and his teenage son. The young daughter is getting married to an older man who was a childhood friend of the father. The police detective is balking at arresting the casino owner because the police detective has fallen in love with the casino owner's wife (the mother of the bride). Every character in the story has a secret that they are trying to hide.
They don't make musicals like that anymore.