I could use some help with dealing with my ex girlfriend.. and her friends...?

[Colby]

It's long, so if you make it through.. props!

Ok so, my ex made out with someone on Halloween night, she sent me a text saying "I was talking to some of the people i party'd with last night and apparently i made out with someone". so i broke up with her over text (not the best idea i know, but i felt disrespected, so i did the childish thing and got revenge that way). than two weeks later i made out with a girl that she really hates, just despite her, (seemed like a good idea while i was drunk..) I wish i had never done it. than she came to my town 2 weeks later with a guy who works in town. and she sent me the text "btw, screw you" so i talked her into having a talk with me. so i picked her up at the guys house and went for a drive and we talked, by the end i could tell that she was very pissed.
So it's been a month since than, and i asked one of her girlfriends if she was doing ok, (my way of checking up on her i guess..) and i want her to not be mad, or sad or anything. and that one day i would make it right, apologize for the revenge acts. than i heard from one of my friends that is a girl, that is also her friend, that there is something on twitter i should see. so she showed it to me. It was between my ex and the girl i talked to. It was covered in lies from the girl to my ex about what i said, that what were going through is a "rough patch" and "he'll wait a little while and try again" and "He's not over you".
The worst part is, my ex ate it up, saying "what an idiot!" and "it's never going to happen". And she texted the friend that showed me the twitter feed "does he want to get back together with me" and she said no. thank god.

Now their all over facebook and twitter, taking pictures with other guys hang off her and saying how great the lives are. and i think their trying to get a reaction out of me.

One problem is, the girl who showed me the twitter feed knows me quite well, and she knows i'm over everything. She also knows that this girl is lying to my ex, but she won't tell my ex that. so now i look desperate and weak.

Truth is i don't have feelings for my ex, i just don't want to come out of this looking weak. i'm strong, i have my pride. I know i've messed up. i just want things to settle out.
Should i say something to my ex about the lies? i'm sure she doesn't want to hear it, and that would probably make me look insecure about everything.
Should i ignore it? It would be for the best if i just moved on i know, but i don't want to look weak so heres my final question, should i fight back? and how?