With my pending marriage, this seems particularly relevant. Secret of longest marriage is saying "sorry".

LONDON (Reuters) – A British couple who hold the world record for the
longest marriage said on Wednesday their success was down to a
glass of whisky, a glass of sherry and the word "sorry".

Percy and Florence Arrowsmith married on June 1, 1925 and will celebrate their 80th anniversary on Wednesday.

 My
hats off to Percy and Florence (ages 100 and 105). 80 years together
and the most telling thing is that they are both living past the
century mark.  That tells me that they are good for each other in
a way that we should all aspire to.

They should write a book on relationships.