If you are a gentlemen/lady

There was once I were on my way home after a seriously long and tired day from school and training.

I boarded the bus and sat down.

The next stop, this really huge/fat lady boarded the bus and occupied the last remaining 4 seats.

Then, at the next next stop, this old lady boarded the bus.

The fat lady stared at me.

I know she wanted me to give up the seat.

I ignored and sleep. Then she tap on me and told me off with a really harsh tone saying, "If you were a gentleman, young man, you'd stand up and let someone else sit down."

I was pissed and I talked back,
 "And if you were a lady, you'd stand up and let four people to sit down."

All other passengers laughed and she gave up her seat and alighted at the next stop. When she's alighted, she cause at least 8 others passengers to alight because there was no room for her to move.