Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: So I've had a best friend since middle school, so for about the past decade, we've been basically brothers. 

Fast forward to a few months ago I was talking to this girl. Someone we went to highschool with, and was kind of part of our group of friends. Me and her got kinda close and were hanging out here and there, not fully a couple, but we made out a few times, talked dirty over the phone and stuff. You know, kind of a light fling. 

We never had sex because she was a virgin (still is as far as I know) and wasn't ready for it yet. (She was raised by a very strict, Christian mom, and pretty sheltered, which manifested in a girl that liked to roleplay kinky sex stuff [she had a major kink for being kidnapped], but not do too much irl, stay with me, that's relevant, I promise.)

Anyway, we do that for a month or two, and my "best friend" (we'll call him "D") dms her on Facebook basically confessing his love for her from hs. So i'm like, "Ok whatever, kind of a dick move, but I dont actually care all that much." And she tells me all of this and said it kind of blew her mind. Again i'm pretty whatever about it.

Then she tells me that he wants her to come to a party with him at his brother's house. This raises a red flag with me for multiple reasons.

 For one, this girl is really sheltered, and would not by any means be able to get herself out of a bad situation, especially in a city she is completely unfamiliar with, about an hour drive from anywhere she knew. (We live in a small town, like, less than 2k people small)

Other red flags are that I've been to a party over there once, and I know that there are lots of drugs and alcohol that go on there, along with underage girls ending up being taken advantage of while hardly concious. (Yeah I wasn't at that party for more than a few minutes) Add to that "D" has personally told me that "as long as you've had at least a sip of alcohol, it's completely ok even if the girl is black-out drunk" referring to getting laid at parties. 

Needless to say, I told her that, in my opinion, it would be a really bad idea for her to go. But that I can't stop her, so if she does decide to go, be really careful, and go in your own vehicle, so she wouldnt be stuck there. 

A few hours later, I get a message from her saying "i'm sorry, I can't talk to you anymore. If you come to my house I will call the police, and be armed with (insert firearm I forgot here)

So obviously i'm completely confused. 

"D" messages "hey" right after.... very suspicious.

So I ask him. He then calls me out for raping her (???) Proceeds to belittle me a whole bunch and talk shit. 

I'm at work so I ignore it till I get off, and message her on something she didn't block me on and ask what happened. She said I raped her and blocked me.

I knew I was innocent (seeing how shes a virgin still) so I call the police and tell them this girl is saying I raped her, so they might wanna go talk to her, cause rape is pretty serious.

This is set still during when #metoo was pretty big, btw

I find out through a mutual friend that she told him that, and he believed her without questioning it. (Btw to anyone that remotely knows me, i'm the last person that you would think would do that. There are people that I am very close to that have experienced rape, it's no joke to me)

"D" Posts on FB and dms everyone on FB he can think of that knows me saying "hey did you know (I) raped someone?" (I found that out cause another friend that was in my passenger seat got that dm from him)

I make a post on FB saying "D is going around saying I raped someone, anyone that knows me knows I wouldn't do something like that. Please ignore him" IK I shouldn't have, but I was mad, and wasn't gonna sit there and accept what he was saying with denying it. (AITA for name dropping him there, after he did it to me everywhere?)

And I even provided evidence (dates and times showing how I never would've had the opportunity to rape her [we were pretty much never alone]) and logic that didn't make sense with her story, and he refused to listen. I understand wanting to believe a girl with this type of thing, especially one you are interested in, but to offer no resistance, even when its directed at someone supposed to be your "brother" even when it doesnt all add up properly, really broke my trust with him.

"D" and the girl do their little fling for a while, then split up, and guess who comes groveling back with "i'm so sorry, I realize now I was wrong" and "give me another chance to be brothers again" But i was having none of it, and cut him off completely. 

I responded with something along the lines of "well i'm glad you realize it now, but no."

What kills me is one of his messages after I told him i'm not going to associate with him anymore: "I dont i'm now what i did to deserve being treated like this"

Is there any basis that I should forgive and forget after that?

Wow that was long, lots of context, sorry about that, it's a very nuanced situation.

TL:DR 
Am I wrong for cutting off a best friend for trying to ruin my life?

cutting off a best friend for good