Well, I'm not really clear on what guilt is or how it feels, but what you're describing sounds like guilt to me. I make fun of my younger siblings all the time. I've made one of them self-conscious about her weight, I've made another one think she's retarded, and on and on. I've never felt anything like what you're describing. Sometimes I guess I feel a little cheap, like what I'm doing is too easy to be fun, but that's all. Feeling sadness and regret for making someone who looks up to you feel bad is definitely non-sociopathic behavior. I'd say you're in the clear.