I have a couple of secrets that I wish I didn't know, one of them has only transpired this week which has prompted this thread.
I know who the father of my friends child is. She doesn't know that I know. The child keeps asking who her father is and friend won't tell them. Now that I know I wish I didn't!
My other one is that (a different) friend of mine has 3 younger siblings. The 4 of them thought they all had the same dad - they don't. In fact there are 4 different dads. My friend knows this but her siblings don't.
It makes me feel so uncomfortable knowing MASSIVE things like this when the people involved don't know which got me thinking, just to lighten my load - what secrets do you know that you wish you didn't!?