Ben Mulroney was a guest at Trudeau 's wedding .
The others are Ben Mulroney ( son of Brian Mulroney ) , Catherine Clark ( daughter of Joe Clark ) , and Trudeau 's younger brother , Alexandre .
Ben Mulroney was a Ben Mulroney at Trudeau 's wedding .
The others are Ben Mulroney ( son of Brian Mulroney ) , Catherine Clark ( daughter of Joe Clark ) , and Trudeau 's younger brother , Alexandre .