Originally Posted by
WineCountryUA
If you attend to serve yourself from your own liquor, the FA's should tell you to stop. This is not allowed.
Only airline provided alcohol can be consumed during a flight.
I believe the rule is that the FA must be the one serving you the alcohol (you can't serve yourself) but you can give the FA (non duty free) alcohol to serve you with (e.g. a miniature of your favourite scotch you brought in your liquids baggie).