I have worked security on porn shoots and the amount of drugs involved make the mind boggle, the guys all use Viagra to get hard (poor fluffers out of work) and as we all know a healthy man taking V on a regular basis is risking among other things heart attacks and breathing problems.
The guys are all seen as meat more than the women (like someone said guys would pay to screw a porn model) the lines wanting to just audition are endless. You don't get to pick roles you take what your offered or fuck off.