Are you a brother-in-law or an uncle (my mother's brother)?

Think about it, your brother-in-law is not necessarily your brother-in-law, and your uncle will always be your uncle.

Your uncle is related to you by blood. Your brother-in-law has nothing to do with you, but a buddy at best.

Of course, whoever you kiss is different from who you kiss. Kinship is related by blood, but good is just good friendship. People who have no blood relationship at all can have good relationships, but after all, there is no blood relationship. )