I met a guy several years back and just fell for him hard. He was so nice and we went out several times. I think I read more into it because he had said he would never introduce his kids to any girl until he was serious - that way they would not be hurt if things didn't work out. When I met his kids after a couple of months - I figured he was serious for sure. He dumped me a couple of weeks later when he told me things were getting serious with someone else and she was involved with his kids already too. I was in shock! He told me we were only friends and has no idea how I thought it might be something more.
I introduced my daughter to Josh early on because of the long distance thing. She was a teen so I just let her know it was fairly casual and she didn't hang out with us much anyway.
I totally agree that it is better to not involve your children for at least several months and until you are exclusive.