is he jealous?

[eulogy]

I have a friend that I sorta had a fling with a couple of years ago (we were sober btw lol) our relationships been a bit weird since and we went for a time when we didn't talk to eachother etc. We agrue way more than normal friends do, sometimes he will do things to spite me, sometimes he will act how he did before we had our fling e.g touching my back, 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, 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.The other day I was around my friends house 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, then my friend said "good I would have been ****** if you gave it to him" I asked him why would he be ****** 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 *******, my friend was telling me this guy was horrible to his ex-gf , I just said" theres two sides to every story and because neither of us know them very well we shouldnt take sides" anyway my friend kept going on, 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?