2. We had a sleepover party at Susan's house.
(Which expression is correct? Are both grammatical?)
Q2: Do only girls have a sleepover? How about boys? Do they have sleepover parties? Do all teenagers have sleepover party in the USA?
Both are correct, but 1. is more common.
Boys also have sleepovers. I don't know about ALL teenagers, but certainly most have sleepover parties.
You can ask a new question or browse more English, Social studies questions.