his theory about how a trauma or attachment to mother can cause a guy to be gay is intriguing. So i could be straight if i could just find where it all went wrong. in my case my mother was not anxious or attached. she did however complain to me about my father frequently. I have always excused this as my role in the family because I understood my father's obsessive tendencies with his work and emotional neglect of my mother through my own personality.
I was also the 3rd son in the family and 5 son in the broader structure. my mom was surrounded by athletic, hard-working men who were not to be found when child-care, housework was to be done. i was the "kitchen window son" looking out at the guys playing soccer in the yard. but someone had to help mom.
I don't think this is the cause of sexual preference as my sexual preference started probably around 4-5 with my earliest memories.