expensive

I was hopping on the ferry one day to go to work and i was on the top deck and bumped into my brother in law who was sitting on the inside seat.  I went over to sit down next to him and notice there was a lady sitting 2 seats down and it was going to be a tight squeeze. I then noticed she also had her handbag next to her and it was going over on to the seat i was going to sit down on. I made my intention clear, at least I thought that i was going to sit down in that seat to talk to my relative.  I gave her a few seconds to move her handbag and when that wasn't forthcoming i sat down anyway.  I got a bit of the handle of her bag as i sat down, she pulled her bag out and exclaimed "expensive handbag!"  I paused for like 2 seconds and said back to her, pointing at my behind "expensive ass".  Turned to my brother in law and we both started laughing.  She went very quiet and didn't say a word the rest of the trip.