Every time I searched for an answer to this I only saw people talking about inviting an NPC to stay over but I'm looking for the other way around. I remember when my sim was visiting his mother's hous...
I believe that is normally a romantic option also it is affected by time of day like after 4:00 PM
Anyway for teen isn't it generations that came with the option to have sleepover BTW it is a party type just like throwing any other party except it is for the younguns