I would never think to moon the giant, but is it okay to shark a friend?

I've been thinking a little about sharking lately. Looking back about a recent match, I realized that I unintentionally sharked a friend during a tournament. He had just won two games and then I joked with him that the third one was absolutely, beyond a doubt, MINE. I wasn't going to go down without winning at least one. He made short order of running down to the eight. But then, he could not sink it. No matter how easy the shot, and I gave him plenty of chances, he just could not get that eight-ball down. Eventually, I got the rest of my balls off the table and won the third game. Just like I said, the third game was MINE.

I thought I was trying to psych myself up and engage in friendly banter, but it certainly didn't improve the way I shot. And I'm very suspicious that I didn't get to him with my comment. Either just planting the seed in his mind, or maybe making him feel just a little sorry for me (ick!!). I definitely don't like the pity angle, but not sure whether the psych out thing, if done in a friendly way, is kosher or not. Frankly, I wouldn't have thought it would actually work. Ultimately, shame on him for letting it affect his play (if that's what happened), but is this just part of the game, or really uncool. Doesn't the banter make the game a little more interesting? What are your thoughts?

Let me just end this post with my favorite sharking line of all time: "You better hurry up and shoot. I just put a whole bunch of ABBA on the juke box." (It worked, too. I guess the guy didn't realize that there was no ABBA in the juke box.)