I've been hit on by a guy once. He was a close friend of a close friend, and I ended up staying at his place for drinks a couple of times after our common friend had left. So once he started asking me about my sexual experiences (I was a virgin back then), so he started talking about how I should try things, etc; and sex isn't necessarily penetration, there's other stuff like blowjobs and rimming, etc.. Then he started telling me that he could help me hook up with some girls he knew.. Then he said, pretending to be charitable, "You know what, I could just do it myself, I could give you a blowjob, give you some experience".. To which I replied no thanks.. the conversation didn't last long after that, then he dropped me off at home. He never was as friendly to me after that, though I didn't really change my behavior towards him..
Anyway, like many people have said in this thread, it was flattering. And, though I'm straight, perhaps under the right circumstances I could've been persuaded to experiment with someone I felt comfortable with, but I didn't trust that guy so much, and he just wasn't attractive enough