This happens to me every once in a rare while when I am out clubbing. I'll be getting a dance from a beautiful girl and for some reason (maybe I've had an extra beer), I won't sport an erection during the first minute or so of the dance. Then I start to panic a bit and worry that the dancer (who is hot) will think she's not doing a good job. So then I'll concentrate too much on getting one (instead of letting it happen naturally), and then I'll really not be able to get one, and things will continue to descend into awkwardness.
In all cases, heading outside for a breath of fresh air--or going to sit at the bar for a bit--will fix things, and the next dance will come off without a hitch. Whenever this happens, though, it's embarrassing as hell. Thoughts?
It's the dancer's job to give you an erection. I find that a blow job usually does the trick.