Guys. I'm sick of this bickering about Gay for pay. All of you are correct, somewhat. The reason is that every performer is different person and is in a different situation. Arguments about labels are circular because people cannot agree what those labels actually mean.
1. Some performers really are completely straight and they are doing porn simply because they are desperate for money. They tend not to last very long in the industry.
2. Some performers are what I like to call "hetero-romantic, bisexuals". They prefer relationships with only woman but can get sexually aroused with both genders. They don't hook up with guys in their private lives for the most part because they are looking for potential relationships and not one night stands.
3. Some performers discover more about their sexuality as they do porn, and change their sexuality after being in the industry. They may truly believe they are straight at the start, but become more comfortable and open after performing for a while. (See: Dante Colle)
4. Some performers are engaged in deception This can be a conscious deception where they know that they are lying about their sexuality, or this can be a unconscious deception where they are lying to themselves about their own sexual feelings. To this very day, there are stigmas attached to non straight sexual labels, so someone may not want to identify with those labels even if they do fit their desires.