I can recall 3 separate times.
(I mean, your mom could have been a stripper... but she's not, right?)
Seriously, though... three total.
Two were one night dealios.
One was a steady thing, but purely sexual. She was a very attractive 33, and I was 24. I learned a good bit from her. It ended when we both acknowledged feelings for one another, and realized it couldn't work.
All three of them positive experiences, but than again - none of them were exclusive.
I'm not sure if I could handle an exclusive relationship with a stripper or not, to be completely honest.