Having a theoretical discussion with my pre teen ....
What age would you leave a sensible teen overnight? Or until 2/3/4am?
Dd thinks once she is 13 she and her best friend who will be 14 should be allowed to stay together overnight instead of having to get a babysitter or go stay with a family member.
For full disclosure, dd and her pal are the most responsible sensible kids I know so no worries about inviting others over etc