It was a top ten hit in the U.S., peaking at No.
This song, sung by the narrator, is about himself, sadly, having to witness the wedding of his former girlfriend to another man.
He plans to kiss the bride, and do everything politely, in accepting the fact that she does not belong to the narrator.
Another interpretation: If you follow the narration, is a father doing all the things the father of the bride does in a wedding: waiting at the altar for the bride to come down the aisle, "silently saying 'I do'.
Other versions have been recorded by Nelson Riddle, Rob de Nijs in Dutch, and by Peter Beil in German.