Siblings will always fuss and fight, no matter how old they get. Even once you're 99 years old, you're still going to yell at your sister for that shirt she borrowed and never returned. But, it's all love. Nobody can tell it like it is to your face like a sibling can. And, in fact, some would say nobody else is allowed to talk to you like that other than your sibling. You can talk crap on your sibling all day, but the second someone else chimes in or even dares agree with you, they're going dow…