Is this a red flag?

[thatonesmummys]

Dp and I having a bicker about something he did in the past when we had just split up, he walks past me glaring at me punching his fists? I don't think he'd hit me, but it's made me think wtf?

That is abusive and violent, and the fact he didn't actually hit you is irrelevant. He was very clearly threatening you with violence. This is 100% NOT OK. Get rid of this asshole.

That's threatening. I would see that as a red flag. How long have you been together?

It certainly does sound threatening, did you feel threatened? (Regardless of whether or not you think he would actually hit you)

Nearly 4 years. I just felt a bit if it was random I don't think I would of thought that much of it. As we were bickering an I said something to bother him then he does it as he's walking out the room I did think wtf why are you doing that!

It's probably nothing but I did find it very odd. I said to him is that what you want to do to me is it, he walked out an didn't reply. We weren't having a full blown argument. We haven't been that good recently he's sly and manipulative when we're arguing I physically cannot argue with him without him blatantly lying and twisting stuff. I've actually felt really put off by him recently

Sly, manipulative and lies. Those are red flags in my book!

God just get rid of him.

Manipulative lying and aggressive
Ltb

You have felt put off by him recently for good reason; you and he should not now be together. There are a lot of red flags flying here re him and he is not going to improve. You're now seeing what his true nature really is.