[Brandye]

Well, my first reaction was somewhat similar to SexGoddess (we seem to agree on many things) only less intense.

Virtually all cultures have taboos on incest. If intercourse and pregnancy result, there are obvious genetic issues. In most cultures brothers and sisters just do not do it. In relatively isolated areas, sibling incest is far from rare.

You have violated a cultural norm. If this has resulted in some sort of hangup, take SexGoddess' advice. Otherwise, be damned careful with whom you discuss it. My brother (younger) and his friends used to peek on my sister (older) and I and we would holler and scream which may have been the whole point. I guess that could have gone farther but doubt it.