I have long suspected that there are straight males who are interested in other men's cocks. This happened when I was in the army and the cock-jokes that went around (besides the jusal heterosexual jokes).
I became more certain that they exist when I went to a stag party for a stright friend for his straight friends not knowing that two of use were gay or bisexual. Straight porno was shown a bit later and one guy just couldn't get over the size of the male actor's cock. It was something to behold.
Other similar events have happened over the years.
A lot of it has to do with who's got the biggest cock? Performance is not an issue here. A close friend and his wife rented The Pizza Boy - He Delivers. He watched the whole thning and then brought it over for me to watch. The first episode is one of the greatest cock-episodes that I have seen.
More recently I found myself on a site devoted to male circumcision. The majority of the guys on this list are straight or at least claim to be -- I have no reason to doubt them. But they share pictures of their own cocks both soft and hard. They know more about the physiology of the penis than I do or at least did as I am learning from this.
I am interested in hearing from others who have had similar experiences.