Am I wrong for this??

I'm needing some opinions on this fucked up scenario going on in my life rn.

So I recently broke up with my ex, who is also my coworker, about a month ago (March 19th). He was an asshole and basically gave up and it started becoming an emotionally abusive relationship so I ran away from that situation before it got worse... A week later we went to a bonfire with our friends on a Saturday and we talked about getting back together, shocking I know 🤦🏼‍♀️ that Monday we talked and decided not to get back together period. 2 weeks pass by and he texts me "hey I got a new phone, text me if you need anything.." I got to thinking 'anything? What is anything?' so I JOKINGLY asked if he would ever do a one night stand.. that topic was talked about for about a week. Long story short, we agreed and shook hands on it and everything... We are now fwb... I'M FWB WITH MY EX WHOM I WORK WITH AND SEE EVERY SINGLE DAY... neither of us are going out with anyone it's just us... NOTE: A majority of ppl at our job knew and loved us being together and now they assume there's something else going on between us bc EVERY TIME he walks past me he just smiles and blushes like when he first saw me and when we first got together...

Oh I forgot to mention I was his first so he's wrapped around my finger real bad... Like asking what I'm doing all the time, even stalking me on the snapmap (which I had to turn off bc of him), and he absolutely freaks out when I hangout with someone, guy or girl. Basically acting like my boyfriend but he doesn't want to be my boyfriend. HE IS CRAZY... Also we've done it 3 or 4 times as fwb..

For those of you who don't know what fwb means Fwb = friends with benefits

Am I wrong to be fwb with my ex especially in this situation??