Others, however, are welcome to join.
Socialization is perhaps the toughest skill to teach.
I always have to prompt my son on playdates, but I believe that he really does want to socialize. He just doesn't know what to say. I also give him general ideas of what to talk about instead of exact scripts. Scripting only teaches him what to say for that one specific time. I'm seeing some improvement, so I guess we are on the right track.