I like the element of surprise. Problem with a dog in the bedroom is the barking. That may keep the BG from opening the door for fear of being attacked by the dog, but it may not. If you crack the door to peek, the dog may distract you when trying to get out.... I think I would keep the door closed and wait for the BG to open it, and then decide whether to attack or not. Keep a cell phone handy for 911, secure the family in your room. If there are children down the hall, I think I'd be following the dog on attack to try my best to save them...
Safety takes a few seconds. Accidents can last a lifetime.
Fondle with care