I... am generally completely oblivious to the opposite sex - or sexuality at all, really. I hardly notice anything or anyone around me. Some coworkers and I will be driving around and they'll be giving themselves whiplash looking at boys while I stare off into space, absorbed in my own thoughts. I almost never flirt, giggle, or blush.
So why on earth did I buy oranges because a cute boy at Safeway told me to? There was certainly giggling and blushing involved on my part, too.