Oh boy I had this discussion at LHR ealier this year...
When I got dressed that morning I was not flying anywhere. I was to pick up our client coming from LHR and meet with our boss at a Frankfurt hotel. FRA is a 2 hour drive for me ánd I was already on my way when my boss called to change our plans - we would be flying to me our client in LHR.
The flight there was not a problem BUT coming back was quite another!!! The inspector insisted I take off my blazer. I pointed out that I was not wearing anything apropreate underneath since I had not expected to fly that morning. That did not interest this guy one bit! So I got a bit cleared " I am only wearing a bra underneath!" "Madam you will still have to remove the blazer...." Hey I had been up since 4 am so this nonsence in the evening was not do any good.
My boss saved the day and got a supervisor to deal with it. When I explain for a 4th time that I had not intented to fly that day, or I would ahve dressed accordingly. I was wanded down and allowed to go on however not without the comment to dress more senceably the next time I fly.... GRRRR That just about did it!!!! My bosses comment was "lets go before you explode..."