Your brother sort of reminds me of this severely Autistic person I met back when I was in the psych ward. He went up to all the members of the female staff asking them per verbatim "I have a proposal for you, a proposal for a commitment, a commitment to a relationship." The severely Autistic person was trying hard to get into a relationship but ended up freaking out everybody else because he had no social skills and he was oblivious to everything. I felt so sad for hi.
Pretty much I had to emotionally hold that guy's hand and make sure he didn't freak out the entire ward. I kept him under my wing when he was in the ward because I remember freaking people out like that being slightly Autistic and lacking social skills too. Maybe you should get your brother checked out. He might be a bit Autistic.
Either that or he's just a regular dub who has Awakeperger's Syndrome. That's my term for social skills that are hampered due to being inside the Borg and who can think nothing else but the Borg and who cannot deal with people who are outside the Borg.