This is for my younger brother. His problem is related to penis. His penis is react when he shows attractiveness and porn. Also his penis is very small. His friend told he is gay but he shared his experience with me. He became nake in front his roommate in hostel several times. He also took their penis in month. They did masturbate by seeing his ass. But no one yet sex his ass. So it is clear that he is not gay. He is very worry about his penis problem. I show his penis and try to help but I can't help. Now plzz suggest me what should I do? What can be reason for not reacting his penis? Plzz help. Thanks in advance.