It is a big deal! To me, that's even an insult to all gay men everywhere! Just imagine if every single time somebody who's gay (like me) would disagree with something by saying "That's so straight"? I just know that would really pissed me off. Just like it really pisses me off when some jerk keep saying " That's so gay". Insulting all gay men everywhere just by saying that is never okay!!! Only a straight guy could say this is not an insult!! If you're straight, then I gotta news for you: Wrong answer pal, or even better: Wrong club dude!! Go visit the Straight love club! Or Girls club, or whatever.