Well hes not your brother so I dont think you broke any rules, technically. Especially since you didnt grow up together.. but thats not what your asking so ill get to my point. It sounds like it made him jealous when you mentioned another guy which sounds like he has feelings for you. It also sounds like its something yall cant do a whole lot about considering he lives with the dad and you live with the mom(im assuming). Its not like yall can profess your want for each other without ruffling some major feathers.. Hes probably wishing he could be with you though.