Its one of those days....

[The Unintelligible]

Lol she's probably just saying she doesn't want him near any of you. They probably got into a fight, and she's contemplating a divorce. Common marital issues. On the other hand, your speculation of him sexually abusing your sister could also be true. But I'd say it's a lower probability.

Anyway, my only suggestion would be to try to reconcile (more specifically trying to mitigate the issues on both ends - i.e. you could try talking to the both of them), or gradually let things fall back into place.

Good luck.

P.S. In the event that this was indeed rape, then frankly their relationship is cold turkey. And it would probably be better off that way anyway.