Impaired Vision

A sex therapist was doing research at the local college when one of the male volunteers told him, "When I get it in part way, my vision blurs. And when I get it all the way in, I can't see a thing."

"Hmmm.

..

that's an interesting optical reaction to sex," said the researcher. "Would you mind if I had a look at it?"So the volunteer stuck out his tongue!