Yes, I agree with Steve, they died of love. The main reason for short life expectancy in the olden times is that people were constantly dying of love.

I sing a version that says:

Her father budged the coffie lid;
her brother unwound the sheet.
And after he kis-sed her many, many times,
Sweet Willie lay dead at her feet.

Of course,it's possible that the father or brother ran a poniard between his ribs or whacked him with a cudgel, but I'm convinced he died of love.