Whatchamacallems

I have a complicated, extended family and my husband coined the term, step-neighbor-in-law, to describe some of the relationships.

But some people need different terms and I wonder what we can use. for those relationships.

Lot's of kids today have step parents, step brothers and sisters, step grandparents, etc. and those terms are generally understood and accepted.

But a lot of couples live together with no intention of getting legally married and, for people with no religious affiliation, that is becoming the norm in our society.

Kids may call their parent's partner by his or her first name, but how do they refer to each other and  tothe parent's partner's relatives? In most cases they just call them by their names, but when mentioning them to other people, such as teachers, that can be confusing.

I wouldn't be surprised if our language develops some new words to  describe those relationships.

If some of those terms are already in use, please let me know what they are.