I think the subject line explains it pretty well.
Aiden Jones at 99 sim days old has been told he's not the messiah, just a naughty little boy, however it hasn't stopped him from romancing the eligible young single females (now mostly with pudding faces) of Riverhills. He now has a wish to travel with his current girlfriend, one Joy Lang. There is no way that she can join the family, as it is already full (and he's the one that has to die to make room for another sim, so I was wondering if sims not part of your family can travel with a member of your controlled family.