Have you ever had a straight actor agree to do movies but walked off the set because he cannot do homosexual things?
Erection problems are common amongst both straight and gay actors. For that, and other reasons, we shoot casting videos of all new and unknown models before casting them in feature films. That is how our CASTING COUCH series got started.
As for straight models walking off the set because they couldn't do gay things; no, that has never happened. They are not inexperienced to gay sex, and they know what is expected of them.
However, we did have an incident with a American gay model one time, whom we had flown to all the way to Spain. At the last minute, he decided he didn't want to do the film anymore. It was after that event that we started shooting castings videos before working with new people. That way, we can avoid shooting feature films with people who have either physical or emotional problems.
Do your straight actors have a problem getting hard ons? How many actors have you ran into that simply cannot get hard?