[Atti's Mom]

I have a question that Im not sure where to post so to the Moderators, I apoligize if this needs to be moved!

Ok..heres the problem. We are going to my Aunts house in Michigan next month for vacation. (we go every year) This will be Atti's first trip. I'm not worried about Atti, I do think he will do fine but my Aunt and Uncle have 4 dogs of their own.

One of her dogs, a male Australian Shepherd, who is getting a little older (maybe 8 or 9) is definately the Alpha of her bunch and last year I noticed him to be somewhat cranky with us as well as the other dogs.

We will stay in her house and have large and seperate sleeping quarters within.(3 bedrooms that close off from the rest of the house but that open to each other) and I will have Atti on a lead whenever we are out and about but my worry is this...what is the best way to handle it if their dog shows aggression to Atti when we are comming or going?
I am hoping that it wont come to having to keep them completely seperated, we are usually outside fishing, swimming and boating during the day and that won't be a problem because Atti will always be with me and other then to use the bathroom or to swim once in awhile, their dog is inside. But at night or when we are going in and out, if their dog does show aggression, how should I handle it without offending anyone? Also, to let you know, my relatives are very laid back and they love animals. They were at my home for a visit in May and absolutely fell in love with Atti and they INSISTED that we bring him with us when we come up.
Other than the problem I had with the neighbors dog comming into my yard, Atti has never shown any aggression, but because I know he will defend himself, Im a little nervous. Any advice would be greatly appreciated!!!! And one more thing....boarding him ir leaving him home are not options. THANK YOU IN ADVANCE!!! :)