Most of the song is pretty self explanatory, clearly about a rich posh girl having a party while her parents are away and she's clearly losing it a bit, but I think the one thing I'd definitely say is that I really believe the "cigarette smoker" is sarcastic and that she's not just smoking tobacco but weed which ties in well with the ending all about the disguise not working. I think it may have been some dodgey stuff or it has just not gone down well with her due to her usually proper sounding environment and that's why she's losing it and that's what he's referring to when he says "how much you've had" etc in the chorus as there is no mention of her drinking throughout the song and that's why there's such strong emphasis on the fact she's smoking.
Most of the song is pretty self explanatory, clearly about a rich posh girl having a party while her parents are away and she's clearly losing it a bit, but I think the one thing I'd definitely say is that I really believe the "cigarette smoker" is sarcastic and that she's not just smoking tobacco but weed which ties in well with the ending all about the disguise not working. I think it may have been some dodgey stuff or it has just not gone down well with her due to her usually proper sounding environment and that's why she's losing it and that's what he's referring to when he says "how much you've had" etc in the chorus as there is no mention of her drinking throughout the song and that's why there's such strong emphasis on the fact she's smoking.