Completely Confused

I met a cancer man at my work. He used to just pick on me left and right all the time and one time I told him he was annoying (because I was having a bad day and his jokes weren't making it better) and he didn't talk to me for a week.

Then he went back to constantly laughing at me and picking on me and flirting with me. Well someone mentioned to him that they thought he was flirting with me and since then he backed off a lot. He barely acknowledges my presence now at work and I am just bitterly confused.

Although outside of work he texts me all the time. At least twenty messages a day about random stuff, not really flirty but he did ask me what I though of him in a joking manner.

Example of one text.

He said he was going shopping. I responded "lol". He goes "what are you trying to say?" I said "What?" He said "are you trying to say you want to go shopping?" I said " well I do love shopping" but that wasnt at all what I was thinking when I responded with my lol text. He then goes "I wouldn't say no if you wanted to come."
I then told him we had company coming and he told me to let him know either way.

Why does he pretty much ignore me at work but invite me out outside of work? He invites other friends a long too so it feels more like a group outing most times. I just want to know if he is crushing on me or if he is just trying to be my friend.

he likes u but he want to keep it on the low for some reason

Well he likes someone else and just wants to be friends. He invites me out with a group of coworkers all the time and he told me he likes someone else so I guess that is what will have to be. I am kind of disappointed but if he isn't interested, he isn't interested.