<human>: I'm moving in with an acquaintance of mine and her two year old dog, who I'll call ShyDog. 

I grew up with cats and a mother who had dog-related trauma and anxiety issues. Meaning that I was raised to think that dogs were all dangerous, waiting to bite/maim you, that if you saw a strange dog loose it would bite/attack you, etc. 

I've come a long way since then and even look forward to one day getting a dog of my own. I can be around dogs in public settings and not be scared, and have had many positive experiences with dogs. 

ShyDog barks and growls at people he doesn't know. I've been to the house a handful of times and now he will wag his tail and follow me around and sit on me, etc, and doesn't bark at me when I come over. 

However we had a bit of a setback the other day when I came over while he was in the backyard, and I opened the door to let him in rather than his mom. He barked and growled at me, and I closed the door and called her over to let him in. He growled a bit at me when she let him in, but we quickly fixed that with a handful of dog food. 

With all of this background I'm worried about how he's going to adjust to me living in the house. I don't know how to get him used to me - I'm worried that he's going to be aggressive to me when my roommate isn't home. She's willing to crate him when she's gone, but that isn't a long term solution - he's a big, high energy dog and I think that quality of life would be terrible for him if he's crated for hours every day.

Summarize the given text in a few sentences.
<bot>: roommate has a shydog, I'm kind of dog shy, how can I get used to him and how can he get used to me? How can I tell if the dog likes me?