Husband’s sister? Or, brother’s wife? Either way, I wouldn’t insert myself into the situation. If it was my husband’s sister, I would discuss it with my husband, like I would with any other friend, but that’s it.
What an awful burden you’re carrying. I feel bad for you: it must be torture to know what’s going on. If only you could erase the images from your mind. If I may ask, how did you find out? Is your sister-in-law aware you know? Has she threatened you if you tell anyone? Be aware, once you tell even one person the secret will be out. Whether or not you decide to talk, I can’t say, but don’t let her threaten you. This situation is not your fault in any way. But this secret you’re carrying must be having an impact on your every day life. I wish I could advise you what to do, but you’re going to have to make that decision yourself. I mean, if you’re close to your sister-in-law, maybe you could let it slide. Again, you are caught in a terrible situation. Your only option is to let time deal with it: at least if you decide this.
I feel your pain and I feel really bad you know all this.
I’m glad she’s cool with you, Starrynitegirl. I still feel you’re carrying a burden, though. Does she seem to realize the position you’re in? I would hate to put someone in your place myself. It is NOT fair on you at all. What happens to you when the sh*t hits the fan? And the worst thing is you’re not to blame. I think you need to address this with her. Don’t go down with her when it’s all out in the open.