Couldn't Follow Through On A Dare

This actually happened when I was younger, but I can't put an age under 18 here. Some of us were at a camp and started talking about sex and cum, and how it tasted. No one admitted to knowing anything about it but we teased the boys a little bit. Then later I got alone with one of them, Jim, and said I might taste his cum if he came on my hand. I didn't touch him at all and so he masturbated a while, it took a long time but eventually he squirted into my palm. And then I couldn't do it! It felt funny watching him, but I was embarrassed that I couldn't finish what I planned, and just wiped it off after looking at it for a minute. He was ok with that though I know he wanted me to try it. I still haven't done that, though I might one day, I just haven't had the nerve.