My friends dont make any sense to me?

I have a group of friends, their cool, a tad on the immature side though, but i am sure that i am to. they think im cool and all, but they've never been a big fan of my personality, im a nice guy, quiet most of the time, monotone voice, so im not very exciting to listen to, but most of all i've never really cared when people say bad things about me, for some reason my friends dont like this at all. They think im trying to play a role where i think im a or something, but im not, its just who i am. Another problem is, say like my friends ask me an opinion on something, like do you think that girls hot? and i say no, well if their opinions different im suddenly gay or a fag or something, its fine i still dont care what they say about me, but honestly ive never done anything truly wrong that should insult them. Thats the 2 main problems, they get mad when i say i dont care what they think about me, and they get mad when my opinion isnt the same as theirs. why do they act like that? they dont invite me to anything or to hang out anymore either, i just dont get it. opinions?