Is it normal to not like someone right off the bat?
This summer, my friend (let's call him Jack) and I have started hanging out with a new group of people he met through a friend a few months ago. For the most part, they're alright people, but there's one of them (we'll call him Adam) who gave me bad vibes from the very start. It's not like he's rude or anything, but for some reason I still think he's an asshole, and I could say a hundred different things that seem wrong with him. Jack seems to get on alright with him though, so I just try not to say anything.
Bottom line, I just plain don't like him. Is it okay, or am I being a douche?