yes, and we were like any other brother and sister really.. i think i played quite a supportive role with him to some extent when we were teens, he struggled to talk to mom and dad about things and we'd sit up late into the night in one of our rooms chatting about stuff... we played together, mostly computer games or lego.
But we did also fight like cat and dog, were singularly vile to each other, knew EXACTLY what buttons to press to piss each other off and quite often went for the jugular.
However, like others, i would have defended him to the hilt, and often did.. his friends were a wee bit scared of me, despite me being 3 years younger than him.. by the time were were 18 and 21 i had absolutely NO qualms about going through people who bullied him for a short cut.
We're extremely close as adults.. might not talk for weeks, but the moment one or the other of us needs something we're there.. we've both gone through relationship breakdowns and offered the other a temporary home for as long as was needed, he was there for me when i needed someone to help me pack myself and my kids up in a single day when i needed to leave an abusive marriage.
we've helped each other through debilitating illness, suicidal thoughts, bullying, abuse, divorces, grief.. he's an complete annoying shithead, but we are each others rock, and thats all that matters.