May I add my non-scientific assessment or observation: There is an adult book store about a half a mile from my home. When I go by, there are usually 10 or less cars in the parking lot during the weekday evenings. Late Friday and Saturday nights are another story. HOWEVER, after Monday night football YOU CAN'T GET IN THE PARKING LOT ! Minimum of 30 to 40 cars.
To complete my field work, I went in there on a Monday night about 11pm after a game. I will admit I have dropped by on a weekend night on a few occasions. That Monday night it was practally standing room only. There were times when there were two to three guys standing around a booth waiting their turn. Now, I am no judge of a guy's sexuality unless he is carrying a purse, but most of these guys appeared to be straight, particually the ones that spent less than ten minutes in the booth, came out and immediatly headed out the front door. Perhaps a little weak kneed also. I can only assume that they got what they came for and that it didn't cost them alot of tokens either.
Thus my conclusion is that a spectator sport where a bunch of fit men in tight pants who tackle and hug each other for three hours, must boost the testerone level to the extent that these guys, who have probabaly watched the game in a bar, just need someone to relieve all that tension before they get home to the wife or whatever. Based on the number of cars in the parking lot late Sunday afternoon and evening during football season, this conclusion might apply also. Sadly, bookstores aren't my thing, so I am left with the fantasy of all those straight boys/men busting a nut, as I drive by.