When my quadruplets were very young they played happily together and were good friends. They enjoyed playing with other children, too, but it involved more effort on my part to arrange for visitors. I usually took the easy way out and just let my four children keep each other company, which they were quite content to do.
By the time they reached school age, however, I was concerned about whether they would make their own friends. I wanted them to maintain a close relationship with each other, but I also thought they would benefit if each child had his or her own friends. I decided to talk to them about friends before school started. We talked about how they would sometimes have the same friends and sometimes have different friends. They were excited about the idea of having their own friends.
When school began I was very happy to see that my children made new friends quickly and easily, but my next concern was whether there would be hurt feelings if only one child was invited to a playmate's house. Again I talked to my children before it happened. I reassured each of them that it was okay to go to a friend's house without the others. They thought that sounded fun, but I was still a little worried about someone's feelings getting hurt.
I soon found out that I need not have worried. They were all very happy regardless of whether one, two, or all four of them were invited to a friend's house. They sometimes went together and sometimes went alone to visit friends and attend birthday parties.