At first, Sunny was an only dog and had the run of the house. He received all the attention and love for about eight years. Then, Charlie was looking for a loving home after being rescued from a less than adequate home. Luckily, Charlie and Sunny got along great from the start. Some aspects of Sunny's life changed, some for the better and some for the worse.
Since Charlie is so much younger than Sunny, by about 10 years, he keeps Sunny young. Keeping up with Charlie insures Sunny can't just lay around on the couch, which he mostly does anyway, and has to run after Charlie. Charlie is really good with letting Sunny have his food first and allowing Sunny to get his treats first. I think this is because Sunny is Charlie's elder and kind of like his mentor. When we first got Charlie, he was very scared and would just cling to certain people for protection. Sunny has taught many things to Charlie, such as how to scratch at the door if he has to relieve himself outdoors, how to be a couch potato, and how to bark if a visitor comes to the door. Not so positive behaviors Charlie has been taught include eating rabbit poop and barking at things that don't exist(just noises they "hear").
One negative aspect of their relationship is that Charlie is always bugging and nagging Sunny. Whether it is chewing on Sunny's fur when they are running or accidentally jumping right on Sunny's head when he is trying to get up on the couch, Charlie is always trying to be near Sunny. I know that Charlie is trying to get Sunny to play most of the time, but I do see how annoying he can be to Sunny. Luckily, Sunny is pretty laid back and doesn't get mad at Charlie.
Over all, the two of them get along just fine and keep each other company!