I can't help myself...

So my friend, I'll call her Molly, is back with her ex.
I never knew the full story, all I really knew was when they got back together another one of our friends, I'll call her Sally, didn't support it and is no longer her friend.

He left her when she had her baby, but mainly because there was a lot of confusing with who the father was. She had had relations with another guy during one of their break ups.

Well Sally told me that Mollys boyfriend used to hit her when pregnant.
I really want to ask Molly about it, but I feel like it's not really my business.
But I can't help myself. I care about her, I don't want her to get hurt again. I didn't know their break up was that seriously.

Fuck. I hate this pickle. I wish I just didn't know.