Every guy is a story to himself.
No doubt, some dudes are gay but pretending that they are str8 for a host of obvious reasons.
The others are bisexual or even str8 but agree to perform in paid for fantasy. They are porn actors, and this is how they are making their living. Some jobs may be more to their liking than the others. Every working person will tell you the same
Yet, the others may just bolt out, and say, no way in hell...
If you remember that this is all a fantasy, there is really no reason to be interested in their individual sexual orientation.