Argh.

Cj and I decided today that we wanted to get a pet, so we went out to PetCo and were looking at birds, when all of a sudden a Dwarf Hamster started to look really good. Now, my Dad's been allergic to rodent dander ever since he got in a car accident when I was in elementary school, and can't even be in the same room with one for very long. I thought about this, but figured we could move the rodent upstairs, or even send him to a friend's house for the weekend if my parents decided to come visit. So we got the hamster, then I called my parents to let them know (give my Dad fair warning for when he comes to visit in May). I got, needless to say, mixed reactions, even when I explained my reasoning to them. My mom asked if I was doing something illicit and didn't want them to see my apartment, and my dad just said, "It's your apartment. You can do whatever you want. I'll just meet you on the street or something." So now I'm feeling really bad, like I did something awful that's making my parents feel estranged from me, and I feel pressured to return the hamster.

Am I out of line here? Did I do something wrong? What should I do?