<< Of course I said no. What the hell does this mean? Is acting nice to people nowadays considered gay? Damn, it's not my fault if I like to treat everyone as my equal... >>
Yep, you're gay but you are in denial.
Don't worry, its happened to me a few times, though it wasn't a really hot chick that asked me. She was fat and fugly. When I said no, she responded "Are you sure?" I should have just told her yes to be a wise ass.
The low point comes when you actually get hit-on or propositioned by a homo. I admit that the first time it happened I lost it and went after the guy. I chased him to his car, the proceeded to do some major damage to his brand new Pontiac while he fumbled to get the keys in the ignition. Its not like I was in a damned gay bar or in a known gay community. I don't know why they don't just stick to their own meeting places where they are reasonably sure that everyone is gay vs. trying to randomly pick-up men in public places that are decidedly NOT gay hang-outs.
As I've grown older and more tolerant, I don't take it too personally anymore. The last time it happened I just said "Um, I'm straight...and you're lucky I'm not 21 anymore because I'd be stomping you into a cement stain about right now."