I'm looking for a word that describes an action where people unintentionally persist with a certain way of doing things or continue to accept a certain practice even though they are aware it should change. Because they continue with it (whatever it is), those who are unaware (or even know!) of the "right" way are given the impression that it is "ok" to carry on with what they do.
An example:
A group of friends gather together for a meal. The "right" thing to do would be to split the bill equally. However, there would be occasions when one person gives a treat (pays the entire bill). Each friend takes turn except for one person. No one brings up the topic but everyone else knows that they should not keep quiet about it. Because they don't address this concern, the friend who does not treat the others continues to think that it is "okay" for him/her to keep doing it since no one says anything.
I have better examples but the topics are more sensitive so I tried to choose a gentler situation.
The word for this is right in the back of my mind but just does not appear! Would anyone be able to soothe the itch in my head for me? :D
EDIT: Sentence Example. The friends who don't address this issue ___ the idea that it is okay for that one person to not give a treat when it is his/her turn to do so.