Many dreams of in-laws will connect to waking-life issues sparked by the relationship you have with them. However, you can go to a deeper interpretation by considering them as character aspects of your own personality. In-laws are similar to parents in a dream, but are more connected to who you chose as a spouse and the challenges of marriage.
(See Family Members.)
To see your in-law in your dream represents a working relationship which can take many different turns.
The dream may also be a pun on being more careful and playing by the rules. You can also apply this meaning to dreams about your current boyfriend or girlfriend’s parents.