Willravel

One should always first ask how they feel about something before one asks how society feels about something, yes? I, personally feel that incest is a negative for several reasons. 1) This represents a dangerous dual role for a sibling. While a sibling can play a friendship role and a sibling role, as they are related (no pun intended), the roll of sexual partner is a whole different psychological ball game. 2) I think everyone knows that incest can lead to genetic irregularities. This, outside of societal rules, would probably be the biggest deterrent.

I doubt that actic's ex was looking to procreate. Sexual attraction isn't 100% connected to procreation, as we can see in the sales of contraceptives around the world. To use simplistic language, some people have an itch they want to scratch. As far as that's concerned, the incest consideration vanishes. One has to fall back on another reason, and I'll bet dollars to donuts that most people would either say something like, "it's gross", or "it's illegal".

I'm curious to ask arctic: what do you find wrong with is behavior? Really, before you make a determination about this, you should organize your thoughts.