Truly curious question, are there actually a lot of incestuous encounters or does that number come from pregnancies/births?

I have very little experience in this. I’m wondering if I’m just a rare case. We are obsessed with our sibling and are actually dating. I want to know if this is something that happens often. The first thing I usually hear is that “incest is a crime” and we won’t end up together. Are there really that many incestuous encounters?