A background in brief; A family friend who we've known for many years has been seemingly happily married for a significant length of time. The couple have no children yet and live in a neighbouring city. They have another set of friends, husband and wife, who we only know in passing but also live in the neighbouring city.
Earlier in the year, FamilyFriend and Wife gave their apologies for several events because they were helping with a personal matter relating to this other couple. A few months later, it was announced that the other couple were separating and the husband moving away. Up to that point, nothing sounded particularly unusual.
But then it transpired that there had been a wife swap going on and that the three remaining individuals were moving in to one property. Finally, as we have now been informed first hand, the three are in a relationship all together. While I have misgivings about all this, ultimately they are all consenting adults and it is entirely their choice.
I have two children, KS1 and Preschool. We meet up with FamilyFriend around once per month, often with his Wife. So depending on just how they decide to run things with Girlfriend now involved, there's a good chance of a question from eagle-eyed DC1 that goes along the lines of "Mummy, why does FamilyFriend have a Wife AND a Girlfriend?"
DH and I are both relatively open minded and we've already had a variety of discussions with DC1 about how families come in different shapes and sizes, covering gay/lesbian couples, blended families, adoption/guardianship, etc. However the idea of reassuring DC1 that families consisting of three adults in a relationship together is perfectly fine doesn't sit right with me.
AIBU to think this? Any suggestions on how to handle the situation would be gratefully received!