"A Billion Wicked Thoughts" book talks about why straight men are interested in sex with men.

There is growing scientific evidence and research being done as to why straight men would be interested in sexual activity with other men. 

http://www.sexualityresource.com/the-strange-new-science-behind-a-billion-wicked-thoughts/

Here is some information from Stephen Snyder, MD

It’s not so unusual these days for a woman to discover pornographic pictures on her husband’s computer.  But the images that one wife found recently were especially shocking.  Her first thought when she found them was, “This is the end of our marriage.”

Her next thought was, “This is the end of civilization.”

The pictures were of nude women, ordinary looking women, except with big erect penises where their female genitals should be.  Some were clearly computer-manipulated photographs.  Others seemed to be some kind of Japanese cartoon.   She’d wasted no time in calling her therapist.

Was he gay?   No.   On the internet, there are enough images of real men with erections, in all possible guises and permutations, to satisfy even the most novelty-crazed gay man.

Was his nature in some way secretly feminine?  Absolutely not.   Women don’t go looking for pictures of erect penises.  A woman may appreciate it when a living, breathing male partner has become erect out of desire for her.   But only after he’s proven his worth in other ways.

So what was the husband’s problem?

When I polled colleagues, their response varied from “Never heard of it, but it sounds pretty sick,” to “Steve, you don’t get out enough. This kind of stuff has been around forever.”

Some light on the subject

Last month I received an advance copy of a new book of sexual research, A Billion Wicked Thoughts, that explores the matter of women with erections and many other sexual subjects using an interesting new method.

In the space of a single year, using publicly available data, authors Ogi Ogas and Sai Gaddam collected the records of 400 million internet searches in the US and elsewhere, and analyzed whatever sexual content they found.

After reading the book, I was convinced I had my answer to the question of what was wrong with the husband who liked to look at women with big erections.

The answer:  Nothing was wrong with him at all.

According to the authors of A Billion Wicked Thoughts, he was the target of a sophisticated internet marketing trick, offering men a novel combination of two ordinary things that many ordinary heterosexual men like to look at:   women’s naked bodies . .  and erect penises.

To read more click here http://www.sexualityresource.com/the-strange-new-science-behind-a-billion-wicked-thoughts/