Is he jealous? (thanks for help in advance)

Ok, basically I have a friend that I sorta had a fling with a couple of years ago (we were sober btw lol) our relationship has always been a bit weird since then and we went for a good amount of time when we didn’t talk to eachother etc. We agrue way more than normal friends do etc and get emotional with it too, sometimes he will do thigns to spite me, or act pissed off more than he should if I do something that was not intende to offend him. Sometimes he will act how he did before we had our fling e.g touching my back.guiding me a lot, putting hats things/on my head or like touching my hand as much as poss but in sorta non obvious ways e.g he put his hand over mine to feel how hot this drink was, anyway one thing he did that confuses me is the way he feels about a certain guy I know. He always moans about the guy for petty reasons, both me and my friend don’t know this guy that well, ( the guy has only ever acted really friendly to both me and him) anyway once this guy took me out the room to ask me something in private (he just wanted to know why I was depressed) my friend saw us talking through the glass in the door, when I came out he asked me what we had been talking about I just shrugged and he shrugged back but looked slightly annoyed. Anyway just the other day I was around my friends house and I was talking about these posters I got for free, I sai I had one left but I already picked who to give it to, my friend automatically assumed I meant the guy, and I said no I meant someone else, then my friend said “good I would have been pissed if you gave it to him” I asked him why would he be pissed and he started going on about what a crap person/ he thought this guy was, I tried defending the guy a bit but my friend was so intent on like making this guy seem like a bastard, even though niether us know the guy very well… Then my friend was telling me this guy was horrible to his ex-girlfriend and used her for sex/gave her fake signals dilabrately, I just said” oh okie but theres two sides to every story and because neither of us know him or his ex girlfriend very well we shouldnt take sides” anyway basically my friend kept saying that this guy was obvs an etc and made it into a bit of an argument, and then he told me if I didnt believe him I should talk to the guys ex about it, he was practically implying I was taking romantic interest in the guy (when I gave no such impression at all) is this just my friend being concerned about me??? I’m really confused. (sorry this post is so long lol) P.s he never really liked the guy before he even heard about the whole situation with the guy and his ex girlfriend