I've slept with my twin brother and it doesn't seem that odd

Growing up me and my twin brother hung out alot, tell each other everything, comfortable around each other, no secrets. Being twins we know each other better than anything and trust each other. So when we started fooling around had sex, it didn't seem different. We still call each other sis and brobro. We still have tons of sibling banter and jokes. It's just one extra thing that happens y'know. People act like incest is the biggest game changed but in reality it's super casual.