There is another piece of evidence you might consider in examining Joseph Smith's sexual behavior.
The following excerpt is from a love letter Joseph Smith wrote when he wanted to arrange a liaison with Newel K. Whitney's daughter Sarah Ann, whom Smith had secretly "married."
It reveals Smith's cloak-and-dagger approach to his extramarital affairs:
"... the only thing to be careful of; is to find out when Emma comes then you cannot be safe, but when she is not here, there is the most perfect safty. ... Only be careful to escape observation, as much as possible, I know it is a heroick undertakeing; but so much the greater friendship, and the more Joy, when I see you I will tell you all my plans, I cannot write them on paper, burn this letter as soon as you read it; keep all locked up in your breasts, my life depends upon it. ... I close my letter, I think Emma wont come tonight if she dont, dont fail to come to night, I subscribe myself your most obedient, and affectionate, companion, and friend. Joseph Smith."
- Joseph Smith Handwritten Letter,
http://www.xmission.com/~research/family/strange.htm