From a few old posts of mine, I'm feeling too lazy to edit together better -
From Lacey Rich (Old time connected gay) -
"At the premiere of Pumping Iron, Tom Minchello had a friend named Margie, who wanted to make it with Arnold. Tom told Margie Arnie's
room number. She went to the suite and knocked on the door. The door opened to a darkened room. Margie could see that a light was on in the bedroom and she could hear moans. She crept to the other door . What does she see; Nothing, but Charles Gaines (author of Pumping Iron & Stay Hungry) and the great Austrian oak with his heels spread to Jesus. She quickly backed up and hurriedly left. By the time she reach the lobby she was in hysterics telling everyone that Arnold was upstairs being f$$ked by a man. I guess that taught Arnie to lock the door."
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He mis spells the name, but the guy is Tom Minichiello, who owned Mid City Gym. He had a book called "Bodybuilders, Drugs, and Sex" where he tells a version of it. Over the years the rumor above got spread around, some say it was Gaines, some say Butler, but the rumor has always been that Arnold went gay for one of the guys from Pumping Iron, and Minichiello saw it.
Bob Bonham heard it was Butler -
http://www.getbig.com/boards/index.php?topic=306303.msg4391490#msg4391490 .
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Tom Minichiello in the Jun 1992 edition of Spy Magazine mentioned that Arnold was connected to Paco Arce, and Arce had pictures of him that Arnold posed for privately - (
https://books.google.com/books?id=K4N6CoFaMwQC&pg=PA8&dq=Tom+Minichiello+arnold+gay+spy&hl=en&sa=X&ved=2ahUKEwjRyLPK7Z3tAhWrQzABHWtjAXEQ6AEwAHoECAAQAg#v=onepage&q=Tom%20Minichiello%20arnold%20gay%20spy&f=false) .
Arce was a millionaire from Spain that was flamingly gay. He'd take briefcases of money around to all the big contests, and try and get bodybuilders to hang out. One of the photos he had of Arnold supposedly has him lounging around in his underwear reading Playgirl magazine -
https://books.google.com/books?id=Xa7j5ofHW0EC&pg=PA63&dq=Paco+Arce+bodybuilding&hl=en&sa=X&ved=2ahUKEwioyIqa753tAhWeRzABHUENAj8Q6AEwAXoECAIQAg#v=onepage&q=Paco%20Arce%20bodybuilding&f=false .
Paco is the guy in the red trunks seen in this famous schmoe shot -

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