Is she cheating on me? Should I be worried?

Me and my girlfriend broke up for a month and a half I left her and she ended up talking to this new boy she works with, they talked for a few weeks had sex, and he eventually stopped talking to her and then we somehow ended up back together, they stopped all communication and unfollowed each other, anyways we got into a argument a few days ago and haven't really seen each other since, anyways I looked on her Twitter and today she refollowed him and he followed her back. I blocked his number in her iphone, anyways the worked together tonight and I checked her recent contacts tonight and he was in there, but she deleted any messages so only i Could see that she contacted him. The number was still blocked though. Could that mean anything? What should I do?

I doubt it means she's cheating. She was probably just upset and reached out for the first person she could think of that would annoy you. She knew you'd find out and she knew it would get a reaction out of you; that's probably why she did it.

The best way to handle it is to pretend you don't notice. Seriously don't even bring the guy up. When she figures out you're not worried about him, she'll probably leave him alone.

Why not talk to her about it, there's definitely something sneaky going on. She might not be cheated but she is being dishonest with you.

Well if she slept with him and now they follow each other. I would think there's something going on talk to her.

I agree, something sounds fishy! I would keep my eyes and ears open! If you ask her she's more than likely going to lie! Not saying it would hurt to ask, but definitely stay alert on this one because the signs say yes!