Respect them and their decisions
Don't offer advice unless asked for.
Do not interfere with the way they handle their jobs or kids ( even if you think otherwise)
Treat their spouses well
Remember they are grown ups and treat them like one
It worth trying to be a friend to them, than mom/dad
Enjoy their company and they will enjoy yours.
Remember their special days call them , gift them and make sure you make them happy with what you say!!
Just accept them for who they are!!