I'm pretty open on it, but most people don't understand what it's about until they see what I'm building. I won't go screaming I'm a afol, but i'll talk about design a lot when I see it, it just has to catch my eye.
My parents and my girlfriend don't mind at all, they even buy me Lego and stuff. She even likes to go with me and spend hours in a local Lego store, hanging around chatting and drinking coffee with the owner.
My coworkers however have mixed feelings about it; I'm a assistant manager at a big supermarket chain, and decided to become that cause I like building big displays (some even won prices), but they sometimes still find it awkward I'll buy Lego in the shopping mall we we are located in. But others are really interested in it and mostly amazed when they see how parts can be used.
My friends think it's cool, cause most of them are in Warhammer 40K stuff, I tried that, but painting isn't my thing. As soon as I would get a kit, I'd cut and glue everything up.
The only ones I sometimes have a problem with are the toytore employees. They give you this weird look, like 'are u retarded or something', when you buy Lego. When they do I'll let them gift wrap it; more work for them, a present for me.