My girlfriend (16/F) Ex friend (15/M) won't leave her alone?

Alright so I been datin this girl for two years now right? I'm 16 Male in 11th grade HS.

Well recently 5 months back she got this new guy friend Whom from here on out i'll refer to my girlfriend as Ashley. Me As Dylan. And her ex friend as Red.

Well 5 months back she got this new friend Red, and apparently they hit it off. And he knew we were dating. Well eventually he wanted to come over and im here thinkin it be awesome! Us 3 hangin out y'know casual crap.

Well instantly the second he arrives I get a bad vibe from him. Hes constantly sarcastic with me, makin me seem stupid till eventually I just say i'm gonna go to my room. He made a stupid comment saying "Kid locked himself in his room already?" To which Ashley responded with "Why are you being so mean?"

After that I closed my door so I don't know what they spoke about. Later they got in a argument. Red told me she could do better then me and then left the place. My mother arrives late for work so after Ashley left about 2 hours after all that.

Now that was on the third week they had met for the first time. And recently he told her how he loved her and whatever. Ashley TO ME Has shown no interest. She ignores him and gave no response as to whether she liked him back or not.

And basically hes been up her arse for the past 4 months hitting on her. And even tried to say he was gonna kill himself for her. To which she asked me for advice.

Me having been like that using suicide to guilt trip people I don't do it no more Saw he was guilt tripping her. So I told her to ignore it and that if you feed him drama it would get worse and so on.

She did and after that he never killed himself and never said it again. So ever since shes come to me for advice. But i'm no magic 8 ball y'know? Well basically he said he ONLY wants to be friends

But I told her NOT to be friends with him that he'd only hurt her more. And he is NOT a good friend to keep around. Well she didn't but he still bugs her And me!!

Hes always sayin to me how he'd be better for her to which I just say I don't care and ignore him and recently his friend that i'll call Shayne messaged me today

Shayne messaged me the BS Reds been spreading saying I been abusing her and crap. And shayne believed it. I told Shayne hes lying and left it at that.

Well now all his friends are fxcking with me and bullying me and its getting to me even though i try to act like it don't bother me

And Ashleys been crying a lot lately. Especially whenever he talks to her. She comes to me and cries. And she gets emotional and shy in his presence

And now theres a rumour my friends said they heard (a group of 5) That Red and Shayne Intended to fight me. My friends said they'd back me up though of course.

And I can clearly beat the crap out of Red And Shayne "I've whooped Shayne before" Haha :) So with my buddies we're all good.

But if I did beat them up pretty bad. I'd seem like the bad guy. And I don't want any police involved. Or even to fight at all. And then with him being beaten the rumours would seem true.

But my main concern is Ashley she keeps crying and Last night she self harmed for the first time... And its really stressing me out.

I asked her if she liked him or wanted to break up And she started crying hysterically so she doesn't wanna do either of those two options.

How can I get rid of Red and Shayne WITHOUT getting Physical and so on. Hes a real smart mouth as well. Hes the type thats NEVER WRONG,

When she told him she doesn't wanna speak to him he said "You will eventually'. Hes cocky and pisses me off really bad... What would you do in this situation?

tl;dr Guy stalking my girl

edit : I don't mean to make him seem like a horrible person. He CAN ACT NICE. But hes a douche bag to as well.

And he isn't doing anything to Woo Her over. Hes been literally begging to be her friend and say sorry. But I told her to ignore it.