Quite right, as long as the couple are happy, that's all matters. No laws are being broken and no-one is getting upset, so I don't understand why some people make it an issue.
Elsa and I are only a few years apart, (I'm 41, she's 37) but Elsa looks about 21 and only 4'9" in height, so we get the stares at the supermarket and on the High Street.