Be not the done thing British old-fashioned phrase informal
Used to refer to a behavior or way of doing something that is not suitable or socially acceptable.
Smoking in the hospital or school is not the done thing.
For your information, spitting in public is not the done thing.
In those days in Asian countries, having higher education was not the done thing for girls.
The verb "be" should be conjugated according to its tense.
If you swallow the bait, you take something that someone offers you, or agree to do something that someone asks you to do without knowing that it is a trick or way of getting something from you.
You can't just do whatever he wants you to do. Don't swallow the bait.