Am I justified in treating my cousin this way?

Okay, my cousin from the UK is over to visit. I haven't seen him in 4 years or so, and I'm 15, so I only vaguely remember him. He is almost 14. He has been over to my house almost every day for two weeks. From 10 or so in the morning till at least 10 at night. Then he goes to my grandma's house. He is extremely frightened of my dogs. They are 15 lbs and 5 lbs. And very nice dogs, but they bark at him when he comes in our house, just at first. He will not be near them. He makes us cage them up all day. It was okay for the first day, but after that it got extremely annoying. Our dogs get really hyper when they are penned up this way all day. He also does not do ANYTHING for himself. He said "(my name), get me a gl of water, will you? I'm your cousin you haven't seen in four years!" as he waved his empty gl at me. I wouldn't have found it annoying, but the way he said it was so..condescending! Like he was better than me, probably because I am a girl. So I said "No. I don't wait on people." Another day, he was running into our house, soaking wet after swimming and threw his towel at me saying, "Hang this up, will you?" I said "You can come back out after you change, and hang it up yourself." He never did. When he ran into our house, our dogs were out so he walked backwards slowly to the bathroom with his hands up, because one of my dogs was following him not barking, not jumping, not growling, just walking. I went to my room to change. I hear him yell "(my name) CAN YOU PUT AWAY THE DOGS?!?!" I come running out and he has the door open about 6 inches with my 15 lbs dog looking at him from the outside, being a good dog. I told him, "They won't kill you, they're 15 pounds!" He says.."Uh..I know! Just before they start barking." I was fed up by this time, so I say "Just a minute, I have to go hang my stuff up" so I go outside and one of my dogs follows me. I have to go catch her, because she had ran off. I come back in, and my cousin is in the basement, away from our dogs. When he was leaving, he goes outside and his towel is laying on the ground. He's with my mom. "Gee, thanks, (my name)" referring to the way I didn't pick up his towel for him. My mother told me this. My grandparents (85 years old!) have been waiting on him hand and foot for the past month, or so. He doesn't do anything to help them. I was very fed up with him. He also lectured me on how it was mean that I told him that I didn't particularly like one of the girls that went with us swimming. He generally acts condescending to me, even though I am a year older than him. He talks like he knows everything about America and insults Americans constantly.(example: Why are all Americans reallly fat or too skinny???) He also gets on my case for saying this like 'I don't know' or 'I don't care' to answer some of his MANY questions....Was I justified? What would you do?