sister and i had an incestual adult relationship and now we dont talk to each other
Family strife happens for many different reasons, and it is a sad thing. One of the risks of any romantic or sexual relationship is that the romance or sex will end, or the entire relationship will end on bad terms. That is why I wrote this. The only way to avoid the risk is to not have any romantic or sexual relationships.
I'm assuming this was consensual sex and that this wasn't a matter of assault. People who are assaulted should put distance between themselves and the abusive person.
Aside from severe discrimination, which, depending on the the jurisdiction, could include criminal prosecution, a bad break-up is the biggest risk of these relationships. Some relationships last, some don't. Some that don't last do not end well. But when these relationships end on good terms, or they last, they are usually intense and incomparable.
As with any other romantic relationship, someone may have trouble seeing their former lover with someone else.
With consanguinamorous relationships, one or more the lovers may experience some internal conflict due to societal biases. External pressures may even force lovers apart, in which case one may stop communication with the other because the heartache or risk of prosecution is too much to endure.
Matters of the heart are often difficult. With consanguinamory, we should stop adding difficulty via discrimination. Instead, we should offer support.