You're his brother. You have a platonic love going on between you two. Every time you're out in public he'd find a way to kiss you or do something to you physical that just feel good to you honestly but you wont admit that in public... Nobody know your both brothers..so when he does do something touchy or PDA it should be okay, right? You're can be little possessive when girls come up to him at the club...and it amuses him when you do that.