PLS HELP ME I HAVE NO IDEA?

If your dad is really having an affair with another woman, then your parent's marriage was in deep trouble long before the affair began. Your mother probably already knows about the other woman or is just turning her eyes another way because she does not want to face the fact of the matter.

You need to realize that this other woman is not the cause of your father's infidelity or marital problems, she is just a symptom of the problems that began when your parent's marriage broke down. Therefore, plotting to physically hurt this other woman is not wise. Breaking up the relationship your father is having with this other married woman is not going to fix your parent's marriage.

I suppose you could find out who she is and go to her husband and tell him she is having an affair. But, what good will that do? She may or may not go away and your father may just find another woman to resume his infidelity.

Let the adults handle this. Whether you realize it or not, your parent's relationship, or lack there of, is already effecting your family life. Unless your father is an award winning actor, things in your home are not functional. Sometimes when a marriage fails, it is the best thing so everyone can move on rather than live in a dysfunctional household where there is not tender love and care.

Here's what you need to remember. I peeked at your other questions and you sound smart enough to at least keep an open mind to what I'm about to say!

Odds that your mom already knows or suspects are extremely high. There are dynamics to a marriage that no teen can fully understand, but just accept this on faith. Your mom wouldn't need to find phone pics to start getting suspicious. It could be anything from a change in his habits (even sexual) to something she notices on a credit card bill to about 1000 other things.

Every expert gives the same advice on this: try to stay out of it. But if this becomes intolerable to you, don't waste your time and energy trying to figure out who she is. She's not even the problem here - your dad is. So if you get to the point where you're about to explode, he's the one you talk to, not your mom.

Obviously, it goes without saying you need to be sure about this. Hopefully, you have a lot more proof than phone pics.

Why don't you let the adults handle the adult problems and you stay on the playground where you belong?
You think like a very young child and you will end up in juvenile detention if you don't learn to behave.

Tell her husband

Tell her husband... trust me ... this is going to make a huge scandal for her.

Don't do anything. If your dad is cheating on your mom, then she must be having her doubts about him . Maybe she is waiting to confront him.
Moreover, no one can escape karma. Let things work out on its own.
If you do anything to that lady, then you may have to face the consequences.

U need to confront your father. Refuse to let him deny it.

Divorce will make a big mess but also keeping the bad news inside you, it will hurt you psychology. You should talk with mom and dad.