Do you ever draw the line?

[MTHeart]

Tried to answer this but don't know where it ended up. I understand boundaries. But DB and telephone coach say don't issue ultimatums. How do I reconcile the two.
I feel like a doormat too. It's ridiculous to think that one adult could find this an acceptable way to treat another adult.

Has anybody had this situation (I'd bet "yes") and how did you handle it. Did ya put your foot down? What were the results? Did you coast along until the A died down? HELP!!!