A husband and wife are having issues in the bedroom. The wife can't orgasm because it's too damn hot.

They see a sex therapist, and he recommends that they have a constant supply of cool air in the bedroom, so the man asks his best friend to waft a towel while he and his wife make love.

Begrudgingly, the friend submits and says yes.
After 20 minutes of lovemaking, the woman is no closer to orgasm, so the friend wafting the towel recommends that they switch places. So the friend is now having sex with the woman while the husband wafts the towel.
After two minutes, the woman starts to tremble and lets out an incredible cry as she reaches the most intense orgasm she has ever had.

The husband looks at his friend, and proudly proclaims, "Now that, my friend, is how you waft a fucking towel."