Kids in different parts of the plane

Are there any rules the airlines have about when kids can be in different parts of the plane to the adults they are travelling with? I'm not talking about toddlers etc. more teenagers and the like.
Of course the decision in many cases will be based on many other factors and I don't want to open up a discussion on the rights/wrongs of abandoning your children
Mine are way too young to be anything other than sat right next to me but have done many flights and at some point will enjoy the freedom and adventure of being semi-"on their own". Just wondered if any have put the kids at the back whilst they sip champagne at the front! What ages were they and how far away from you - probably a huge difference between being at opposite ends of the plane and just having a curtain separating you!
Of course the decision in many cases will be based on many other factors and I don't want to open up a discussion on the rights/wrongs of abandoning your children

Mine are way too young to be anything other than sat right next to me but have done many flights and at some point will enjoy the freedom and adventure of being semi-"on their own". Just wondered if any have put the kids at the back whilst they sip champagne at the front! What ages were they and how far away from you - probably a huge difference between being at opposite ends of the plane and just having a curtain separating you!