He's got a girlfriend, I'm confused

Hey, so I'm just wanting some advise really. I was in a relationship for 10 years (my child's father) and before him, I never dated and I mean ever. So I broke up with my ex early last year and it devastated me as I didn't want to end it. Anyway, that's done and I'm moving forward.

I feel like I'm ready to get out there. I'm not entirely sure what I want or looking for ect, but I know I would like to give it a go.

I did meet someone in work and we immediately hit it off and I've got to be honest, I've not had that with anyone so it was like wow. For weeks, we spoke everyday about all kinds, he gave me his number and the flirty banter was so much fun too. It was really nice to have someone want to get to know me, for me and not just the general chat. I felt a connection. Even my co-workers mentioned they thought there was something between us. They said we had a vibe and could tell me like me ect. So there is me, all happy (realising my ex was wrong, and that there are people out there that would want me despite him saying they wouldnt).

Then one day, he said he wanted to be honest with me, and told me he had a girlfriend. Shocked was an understatement. I know I have no experience but he didn't act or speak to me like he was taken. In my opinion, if I was in a relationship with someone. I would not have taken the time or effort like he did with me. Some of the things he said, I wouldn't expect from someone in a relationship. He also said he would of gotten to know me more if he didn't have a girlfriend as he thinks we hit it off immediately. Honestly baffled me. So he said he it wouldn't effect how he's been with me, which I thought extremely weird. So I backed off as I will never be that women who tried to get with someone in a relationship. I thought I will treat him like a friend as we did hit it off and I really liked speaking to him. So I had to remind he him couldn't say things to me as it was inappropriate then.

I mentioned one day that I had a date and he was shocked then asked me loads of questions. Then after would ask me load more questions about it and if there was another. He then started being weird with me and wouldnt talk properly for a couple of days. I pulled him up about.it because I can't hold my Tongue lol and now.hes back.to normal.

I know I'm rambling, my head is pretty confused. So I met up with an old college friend as it seemed he needed someone to listen and he then asked me out. Which I don't know. Its stupid.to say, but I didn't get the vibe that I had with my.work person. I didn't get any romantic vibes at all from him. I know I.shouldnt compare but I can't seem to get the work lad out.of my head. I really don't know why as i know he's taken and I will never act upon it. I don't know.if it's because he's.the first person I've liked other than me ex.

So thoughts and advise would be great tbh. Xx