Is ex attempting to make me jealous?

[Christina]

Long story short, my ex boyfriend dumped me over a year ago. He subsequently told me he just wanted to stay “friends”. Following our breakup, I started seeing another guy. When my ex found out, he got really angry and started posting disrespectful things about (calling me a hoe etc). It even came so far as him coming to a cafe where I was at, because his friend had told him.
I decided to delete him off facebook because I was fed up with the whole thing and didn’t have any contact with him. In February, however, my ex suddenly started following me on twitter. He wrote to me and asked me how I had been and how uni was going.

Every time I would write with one of my guy friends, my ex would start chatting up another girl or posting a photo, which was related to what my friend and I were talking about. I decided to ignore it. However, for some reason he’s been following random girls on twitter since then and chatting them up. Does it sound like he’s trying to make me jealous by doing these things?