So Hard to Be a Group of Three

Reese wanted her friend from next door to come over and play.  The problem is that friend is also her brother's friend.  Most of the time they all play together, but sometimes, it is just the girls or just the older two and one of them feels left out.  It is inevitable; I have heard it since I was young, three is not a good number of playmates.  I have seen it time and time again with different groupings and pairings of kids.  I know that it is hard to share a friend, and I also know that Riley needs one probably more than Reese.  He wants friends to come and play at our house, but he does not like for Reese to tag along.  I told him that maybe in a few weeks, we would go and visit our friends who have boys his age and a girl Reese's age so that he would get some play time with just boys and his sister not bothering him.