When I was in college, I was staying a summer in DC, and a super petite girl who was famous for getting around came and stayed with us. We'd been flirting all night, and about 30 minutes after we crashed, she crawled into my bed. After giving her what at least appeared to be back-breaking sequential orgasms from oral, I figured I was in, but she turned me down, settled for a pretty spectacular blowjob.
"OK," I thought, "maybe some of the rumors aren't quite true, and she doesn't put out on the first date." The next day we hung out on the Mall for 4th of July, and on the ride back we got stuck in traffic. She went down on my while I fingered her as we inched through. Got back to the house, she turned me down again. Now I was perplexed, but whatever.
Wasn't until 6 months later, when she was fucking a friend of mine, when she apparently mentioned to him that she turned me down because I had the biggest dick she'd ever seen, and she'd had painful sex from smaller, but still large, ones. One of the nicest things anyone has ever said about me.
We ended up fucking at the end of senior year. By then she'd discovered lube.