The day after the Tantric Massage, my wife asked me how many of the men in the Yoga and Massage classes are gay. My answer: "Don't know, don't care. That's not what it's about. Plus, it's none of my business."
The way to get the most out of either the Tantric Yoga or Massage is to give yourself permission to relax into it. If your cock gets hard, welcome it, embrace it, enjoy it, be proud of it. An erection is the most natural of male physiological functions.
Men - all men, regardless of sexual orientation - need to understand this. Stop worrying about whether you, or any guy in the vicinity, has a hard-on. It has nothing to do with being gay or straight and has everything to do with being a man.