I actually read the whole thing, and this is how I pictured each of the main cast:
OP

Fabio

Joey

In my opinion, Hulk obviously has some issues, and if you and gorgeous want to put up with him, that's your prerogative. He obviously realizes that you're better friends with each other than with him, so you two could, in his mind, cut off contact with him completely and be perfectly fine with that. That scares him, and while he inconsiderately babbles on about his love of cars and whatnot, he's simply trying to wow you into liking a subject that he does. It's only his social ineptitude that makes him all what you described, and whether or not you want to undertake the burden of helping him learn to properly socialize is your call. However, ditching him now is what he fears most, and if you do that, you're going to blindside him pretty bad.