Following the exact instructions.

This idiom or expression means:

Completely.
The whole thing.

When someone says “We bought it hook, line, and sinker,” they mean something like “We believed the whole (false) story.”

This expression is used with verbs like buy, accept, fall for, etc., and has to do with being deceived.

This idiom or expression has to do with:

Disrespecting.
Doing or saying the wrong thing.

I don’t care who he is. He crossed the line and has to apologize.

Also:
Joining the other side.

If this infighting goes on, some of the voters will cross the party lines and vote for the other party’s candidate.