We sometimes forget that it needs a little bit of communication to make things work.
Just because the two adults get along well it does not mean the chemistry is perfect with the kids.
My stepdad, whom I call simply "dad", was younger than my mom, did not have any kid himself, raised as the only child in his family and then he met mom.
The married and he become part of our family.
Just like that?
No... We had to sit down and have a "presentation" and a few "directives".
1. "Mom marries this guy, not you. So you should first of all check with me if anything bothers you."
2. She told us that he never had any children so he don’t know how hopeless impossible or how perfectly wonderful we can be at times, so we should concentrate on the later to begin with.
3. They told us how they met, from where he came and how he grows up, so we could catch up a little on the story.
I and my sister was 6 and 8 at the time.
By that, we had been introduced. We suddenly know a lot more about this guy, the ice was broken, no fears and it went very well.
Talking to kids about grown up matters does help, and asking us as kids to be supportive before it is needed is just as important.
Funny thing is - today I have a better relation to my stepdad than to my mom.
Until this point - get a baby sitter. As mom said - she wanted this guy, not us, so we should be very much out of the picture until things get really serious.