I'm sorry you're dealing with that. Whether she thinks you were hacked or posted the stuff yourself, she should learn not to spread it around.
Because she's not certain if you were hacked, she knows she might potentially be showing your future father-in-law (and others) secrets about your sexuality, which isn't appropriate and kinda rude in my opinion. I'd be mad.
I'd just tell her that you were hacked and it was posted by someone else. AND if she sees something like that in the future to bring it to your attention FIRST. It's probably better in the long run to keep her out of your sex life.
ugh.. Mother-in-laws.. I feel ya.
I've almost had my cover blown with family;
I have a facebook page that I made for Eden so I can like and share things and participate in contests without my very conservative family seeing. And I thought I associated that login here with Eden so stuff would post to that account only.
So apparently when you like something on Eden, Eden takes the liberty of posting that to the timeline of ANY account that is currently logged in on your computer, without any sort of permission asked.
Luckily my cousin and a friend started commenting on my activity pretty much immediately, and they thought I was being hacked so I was able to remove it right away before everyone saw.
I'm really careful now to make sure which profile I'm signed into, and as backup I went and changed permission of my personal FB so that Eden cannot post publicly to my timeline.
I wish there was some sort of permission asked in the first place though.