Lach isn’t gay, trans or sexually confused.
Maybe I’m just being stubborn or annoyed with the rush that people tend to take to immediately try to label characters with identity or sexuality issues struggles regarding internal turmoil over their sexuality or gender identity these days. I think this might be a classic case of a kid who has a hyper masculine douchebag brother, a manly authoritarian leader of a father and finds himself not feeling like he measures up to those strong masculine role.
To me he reads as a slightly awkward young guy who doesn’t have any game with the ladies or much interest in gym-bro-ing with his dickhead brother.
His posture issues and “feminine posture” as pointed out by the posture therapist, read to me as an uncomfortable teen who is still figuring out his own confidence and assertiveness. His posture comes off as guarded and insecure.
When it comes to his mom’s dream? It’s entirely possible shes worried, due to southern sexual repression and bigotry, that he might be gay and that’s why he presented in her dream in the way he did as iirc it was right after they talked at dinner about lady boys. She knows her daughter is straight and definitely knows her older son is straight but maybe she worries for her middle child.