Bill's Family

Problem

Bill, in his middle-age, marries a young lady but divorces her soon after.

Bill's son marries the young lady's mother.

What is:

$(\text a): \quad$ Bill's relationship with the young lady's mother?

$(\text b): \quad$ Bill's relationship with his former wife?

Solution

Bill is simultaneously:

$(\text a): \quad$ the father-in-law of his ex-mother-in-law

and:

$(\text b): \quad$ the stepgrandfather of his former wife.