This idiom or expression has to do with:

Helping, as in:

I’m tired of bailing you out of your problems. Next time call someone else!

Also, related:
Helping someone out of jail by paying the bail money.

This idiom or expression has to do with:

Leaving them.
Abandoning them.

My wife has bailed out on me!

This idiom or expression has to do with:

Quitting, as in:
After only one week on the job he bailed out.