DD(12) is going to stay with some Spanish friends in Spain for a week. They have 3 DC, 12, 10 & 7.
I have just had an email asking if it's ok if they go out one night and leave DD home alone with their DC. Apparently it'll be for 3 hours and they're used to doing it.
I spoke to their DS(12) who's staying with us at the moment. It seems the 3 hours is probably going to be until the DC go to bed, not the whole time they'll be out.
DD stays at home during the day on her own, but she's never been left alone in the evening/night. I don't leave DS(9) alone at all yet.
I don't feel comfortable with this but not sure if I'm being overprotective. Their DS was surprised that I wasn't sure and told me that they're not 5. 
WWYD?