scared or aggressive??

Two weeks ago, my 6 month old weimaraner barked at my roommate's son when he came in my room to tell me good night. Now, he does it almost everytime he comes in the room to tell me goodnight. It is a high pitched bark, not a growl. He does not raise his hair. Any other time, my dog loves my roommate's son. He has never shown any signs of aggression towards him. I'm worried that he will become aggressive. What should I do? and Why is he behaving this way? HELP ME PLEASE!

She is probably neither. She sound most likely like she is alerting you to his entering. If you didnt correct it the first time it happened she probably thinks she is doing what you want. What do you do when she dose this? If you are acting nervous when she dose it on account of you worrying about why she is doing it she may interpret this as you being nervous from him entering and this could cause her to start to become protective of you and your bedroom from him. Next time give a firm but calm "no" and maybe snap your fingers as you say it. Do it at the first sign she is about to bark or on her first bark. Then if you think its safe have him sit next to you and see what happens. if she barks again give her another "no" I hope this helps. Pleas let me know.

I have asked many people about this, and they all seem to say about what you said. Snap and give a firm no but don't over reprimand. We have started doing this, and also my roommate's children are coming in my room more often. They are allowed to watch TV for 30 minutes before they go to bed, so they are coming in my room to do this. Also, in the mornings before they go to school they come in my room. Rainer has calmed down quite a bit about other people being in my room. Thank you for your reply and your help!