My friend and I (we'll call her Ellie) have been friends for years. I've even considered her my best friend and assumed that she thought the same way.

A couple months ago, I broke up with my boyfriend. I was kind of upset, but moved on. Yesterday, I was told Ellie and my ex were dating. I was told over text. I was honestly hurt and betrayed. Not. Necessarily because they were dating, but because she didn't tell me. I ignored her while she blew up my phone with things from "I am so so sorry" to "please answer me."

Today, I had other friends help me send a message that went like this "Yeah I am sort of upset that hurt, not the fact your dating him but because you didn't tell me and it's like you were hiding it. On the Fun day, you were kind of a jerk too. You made the joke that I was putting boys over you, but that's basically what you did. I tell you everything and you hid this from me for however long. So yeah, I'm frustrated and hurt."

After I sent that, my ex started tearing me apart in messages. I was surprised and angry. Ellie sent a message that showed genuine regret, but I was still hurt, so I replied with this "Maybe if you would've told me, it wouldnt have been as big of a deal, but you're someone really close to me and you kind of hid that from me. I do hold grudges and I think I've told you that. If I forgive you, it's going to take a while. But that's if I decide to forgive you at all. But you have no idea how much it hurts and how betrayed I feel about it. I'm really pissed and probably won't talk to you much, if at all in school. And if your boyfriend picks another fight with me you and I are done for good."

She called me, crying, and begging me not to ruin our friendship. Honestly, I feel like it's an unspoken thing that friends don't go behind each other's backs and date their exs. They are both upset with me, but I hold grudges and she knows that. And just like crows, I hold grudges for years.

Now Ellie and my ex are both mad and upset and saying I'm the AH. So, people of Reddit, should I apologize and forgive , or should I cut my losses?