<human>: I'm shaken by what happened today.

So, I have a little dog. She's a 2-year-old 13-pound bichon-maltese-poodle-something. We adopted her from a rescue about 4 months ago and she's quite anxious & fearful--jumps at the slightest noise. We have to keep her away from kids completely because she will lunge and bark (which sucks). But other than that, she's never bit or even snapped at me or my husband before. She's a good girl.

Today, I was sitting with her on the bedroom floor. My husband happened to walk into the room quickly and purposefully, and the dog jumped up and started barking at him very aggressively. We were surprised--all he did was walk in.

So I guess this is where we made the mistake. We agreed, "let's try to desensitize her to you walking into the room." So we did it again--my husband walked into the room again quickly and purposefully had an aggressive air about him when he did it. This time the dog didn't really do anything. "Good," we thought--she's getting used to it.

We did it a third time and this time she jumped up and barked like I've never heard her bark before, and she jumped up and BIT HIM on the thigh--a real bite--he has a bruise! We were completely shocked that she would bite her owner, just for walking into the room!

Now, in retrospect, we are thinking--maybe we were provoking her by repeating the action? But we've used desensitization before to help her with other fear issues--like with the vacuum and statues (yes, she was afraid of statues in the park).

I'm also shocked that she would BITE her owner!! She has a great relationship with my husband. He is a calm and even-mannered person. He has *never* hit her or even spoken to her angrily!

Should I be worried? Or is it ok since it was an unusual, particular behavior that provoked her do this? 

Also, I can't get a behavioral therapist. Can't afford it.

Summarize the given text in a few sentences.
<bot>: My dog bit my husband for real when he (my husband) quickly walked into a room with a purposeful attitude.